EventList.cpp

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2018 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidDataObjects/EventList.h"
#include "MantidAPI/MatrixWorkspace.h"
#include "MantidDataObjects/EventWorkspaceMRU.h"
#include "MantidDataObjects/Histogram1D.h"
#include "MantidKernel/DateAndTime.h"
#include "MantidKernel/DateAndTimeHelpers.h"
#include "MantidKernel/Logger.h"
#include "MantidKernel/TimeROI.h"
#include "MantidKernel/Unit.h"
#include "MantidKernel/WarningSuppressions.h"
 
#ifdef _MSC_VER
// qualifier applied to function type has no meaning; ignored
#pragma warning(disable : 4180)
#endif
#include "tbb/parallel_sort.h"
#ifdef _MSC_VER
#pragma warning(default : 4180)
#endif
 
#include <algorithm>
#include <cfloat>
#include <cmath>
#include <functional>
#include <limits>
#include <stdexcept>
 
using std::ostream;
using std::runtime_error;
using std::size_t;
using std::vector;
 
namespace Mantid::DataObjects {
using Types::Core::DateAndTime;
using Types::Event::TofEvent;
using namespace Mantid::API;
 
namespace {
 
constexpr double SEC_TO_NANO{1.e9};
 
// minimum event vector length to use tbb::parallel_sort
// this is 4x what parallel_sort uses in the indidividual blocks
constexpr size_t MIN_VEC_LENGTH_PARALLEL_SORT{2000};
 
template <typename EventType>
int64_t calculateCorrectedFullTime(const EventType &event, const double tofFactor, const double tofShift) {
  return event.pulseTime().totalNanoseconds() +
         static_cast<int64_t>(tofFactor * (event.tof() * 1.0E3) + (tofShift * 1.0E9));
}
 
template <typename EventType> class CompareTimeAtSample {
private:
  const double m_tofFactor;
  const double m_tofShift;
 
public:
  CompareTimeAtSample(const double tofFactor, const double tofShift) : m_tofFactor(tofFactor), m_tofShift(tofShift) {}
 
  bool operator()(const EventType &e1, const EventType &e2) const {
    const auto tAtSample1 = calculateCorrectedFullTime(e1, m_tofFactor, m_tofShift);
    const auto tAtSample2 = calculateCorrectedFullTime(e2, m_tofFactor, m_tofShift);
    return (tAtSample1 < tAtSample2);
  }
};
} // namespace
//==========================================================================
//==========================================================================
bool compareEventPulseTime(const TofEvent &e1, const TofEvent &e2) { return (e1.pulseTime() < e2.pulseTime()); }
 
bool compareEventPulseTimeTOF(const TofEvent &e1, const TofEvent &e2) {
 
  if (e1.pulseTime() < e2.pulseTime()) {
    return true;
  } else if ((e1.pulseTime() == e2.pulseTime()) && (e1.tof() < e2.tof())) {
    return true;
  }
 
  return false;
}
 
// comparator for pulse time with tolerance
struct comparePulseTimeTOFDelta {
  explicit comparePulseTimeTOFDelta(const Types::Core::DateAndTime &start, const double seconds)
      : startNano(start.totalNanoseconds()), deltaNano(static_cast<int64_t>(seconds * SEC_TO_NANO)) {}
 
  bool operator()(const TofEvent &e1, const TofEvent &e2) {
    // get the pulse times converted into bin number from start time
    const int64_t e1Pulse = (e1.pulseTime().totalNanoseconds() - startNano) / deltaNano;
    const int64_t e2Pulse = (e2.pulseTime().totalNanoseconds() - startNano) / deltaNano;
 
    // compare with the calculated bin information
    if (e1Pulse < e2Pulse) {
      return true;
    } else if ((e1Pulse == e2Pulse) && (e1.tof() < e2.tof())) {
      return true;
    }
 
    return false;
  }
 
  int64_t startNano;
  int64_t deltaNano;
};
 
struct FindBin {
  double divisor;
  double offset;
  std::optional<size_t> (*findBin)(std::span<double const>, const double, const double, const double, const bool);
  FindBin(double step, double xmin) {
    if (step < 0) {
      findBin = Mantid::DataObjects::EventList::findLogBin;
      divisor = 1. / log1p(abs(step)); // use this to do change of base
      offset = log(xmin) * divisor;
    } else {
      findBin = Mantid::DataObjects::EventList::findLinearBin;
      divisor = 1. / step;
      offset = xmin * divisor;
    }
  }
 
  std::optional<size_t> operator()(std::span<double const> X, const double tof, const bool findExact) {
    return findBin(X, tof, divisor, offset, findExact);
  }
};
 
// EventWorkspace is always histogram data and so is thus EventList
EventList::EventList(const EventType event_type)
    : m_histogram(HistogramData::Histogram::XMode::BinEdges, HistogramData::Histogram::YMode::Counts),
      eventType(event_type), order(UNSORTED), mru(nullptr) {
  switch (eventType) {
  case TOF:
    this->events = std::make_unique<std::vector<Mantid::Types::Event::TofEvent>>();
    this->weightedEvents = nullptr;
    this->weightedEventsNoTime = nullptr;
    break;
 
  case WEIGHTED:
    this->events = nullptr;
    this->weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
    this->weightedEventsNoTime = nullptr;
    break;
 
  case WEIGHTED_NOTIME:
    this->events = nullptr;
    this->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
    this->weightedEventsNoTime = nullptr;
    break;
  }
}
 
EventList::EventList(EventWorkspaceMRU *mru, specnum_t specNo)
    : IEventList(specNo),
      m_histogram(HistogramData::Histogram::XMode::BinEdges, HistogramData::Histogram::YMode::Counts),
      weightedEvents(nullptr), weightedEventsNoTime(nullptr), eventType(TOF), order(UNSORTED), mru(mru) {
  this->events = std::make_unique<std::vector<Mantid::Types::Event::TofEvent>>();
}
 
EventList::EventList(const EventList &rhs) : IEventList(rhs), m_histogram(rhs.m_histogram), mru{nullptr} {
  // Note that operator= also assigns m_histogram, but the above use of the copy
  // constructor avoid a memory allocation and is thus faster.
  this->operator=(rhs);
}
 
EventList::EventList(const std::vector<Types::Event::TofEvent> &events)
    : m_histogram(HistogramData::Histogram::XMode::BinEdges, HistogramData::Histogram::YMode::Counts),
      weightedEvents(nullptr), weightedEventsNoTime(nullptr), eventType(TOF), mru(nullptr) {
  this->events = std::make_unique<std::vector<Mantid::Types::Event::TofEvent>>(events.cbegin(), events.cend());
  this->eventType = TOF;
  this->order = UNSORTED;
}
 
EventList::EventList(const std::vector<WeightedEvent> &events)
    : m_histogram(HistogramData::Histogram::XMode::BinEdges, HistogramData::Histogram::YMode::Counts), events(nullptr),
      weightedEventsNoTime(nullptr), mru(nullptr) {
  this->weightedEvents = std::make_unique<std::vector<WeightedEvent>>(events.cbegin(), events.cend());
  this->eventType = WEIGHTED;
  this->order = UNSORTED;
}
 
EventList::EventList(const std::vector<WeightedEventNoTime> &events)
    : m_histogram(HistogramData::Histogram::XMode::BinEdges, HistogramData::Histogram::YMode::Counts), events(nullptr),
      weightedEvents(nullptr), mru(nullptr) {
  this->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>(events.cbegin(), events.cend());
  this->eventType = WEIGHTED_NOTIME;
  this->order = UNSORTED;
}
 
EventList::~EventList() {
  // clear this out of the MRU (copy of code from EventList::clear()
  if (mru) {
    try {
      mru->deleteIndex(this);
    } catch (const std::runtime_error &) {
      // this is an ignorable error
    }
  }
 
  // set all member vectors to nullptr
  this->events.reset();
  this->weightedEvents.reset();
  this->weightedEventsNoTime.reset();
}
 
void EventList::copyDataFrom(const ISpectrum &source) { source.copyDataInto(*this); }
 
void EventList::copyDataInto(EventList &sink) const {
  sink.m_histogram = m_histogram;
  if (events)
    sink.events = std::make_unique<std::vector<Types::Event::TofEvent>>(events->cbegin(), events->cend());
  else if (sink.events)
    sink.events = std::make_unique<std::vector<Types::Event::TofEvent>>();
  if (weightedEvents)
    sink.weightedEvents =
        std::make_unique<std::vector<WeightedEvent>>(weightedEvents->cbegin(), weightedEvents->cend());
  else if (sink.weightedEvents)
    sink.weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
  if (weightedEventsNoTime)
    sink.weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>(weightedEventsNoTime->cbegin(),
                                                                                   weightedEventsNoTime->cend());
  else if (sink.weightedEventsNoTime)
    sink.weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
 
  sink.eventType = eventType;
  sink.order = order;
}
 
void EventList::copyDataInto(Histogram1D &sink) const { sink.setHistogram(histogram()); }
 
// --------------------------------------------------------------------------
void EventList::createFromHistogram(const ISpectrum *inSpec, bool GenerateZeros, bool GenerateMultipleEvents,
                                    int MaxEventsPerBin) {
  // Fresh start
  this->clear(true);
 
  // Get the input histogram
  Mantid::HistogramData::HistogramX const &X = inSpec->x();
  Mantid::HistogramData::HistogramY const &Y = inSpec->y();
  Mantid::HistogramData::HistogramE const &E = inSpec->e();
  if (Y.size() + 1 != X.size()) {
    throw std::runtime_error("Expected a histogram (X vector should be 1 longer than the Y vector)");
  }
 
  // Copy detector IDs and spectra
  this->copyInfoFrom(*inSpec);
  // We need weights but have no way to set the time. So use weighted, no time
  this->switchTo(WEIGHTED_NOTIME);
  if (GenerateZeros)
    this->weightedEventsNoTime->reserve(Y.size());
 
  for (size_t i = 0; i < X.size() - 1; i++) {
    double weight = Y[i];
    if ((weight != 0.0 || GenerateZeros) && std::isfinite(weight)) {
      double error = E[i];
      // Also check that the error is not a bad number
      if (std::isfinite(error)) {
        if (GenerateMultipleEvents) {
          // --------- Multiple events per bin ----------
          double errorSquared = error * error;
          // Find how many events to fake
          double val = weight / E[i];
          val *= val;
          // Convert to int with slight rounding up. This is to avoid rounding
          // errors
          auto numEvents = int(val + 0.2);
          if (numEvents < 1)
            numEvents = 1;
          if (numEvents > MaxEventsPerBin)
            numEvents = MaxEventsPerBin;
          // Scale the weight and error for each
          weight /= numEvents;
          errorSquared /= numEvents;
 
          // Spread the TOF. e.g. 2 events = 0.25, 0.75.
          double tofStep = (X[i + 1] - X[i]) / (numEvents);
          for (size_t j = 0; j < size_t(numEvents); j++) {
            double tof = X[i] + tofStep * (0.5 + double(j));
            // Create and add the event
            // TODO: try emplace_back() here.
            weightedEventsNoTime->emplace_back(tof, weight, errorSquared);
          }
        } else {
          // --------- Single event per bin ----------
          // TOF = midpoint of the bin
          double tof = (X[i] + X[i + 1]) / 2.0;
          // Error squared is carried in the event
          double errorSquared = E[i];
          errorSquared *= errorSquared;
          // Create and add the event
          weightedEventsNoTime->emplace_back(tof, weight, errorSquared);
        }
      } // error is nont NAN or infinite
    } // weight is non-zero, not NAN, and non-infinite
  } // (each bin)
 
  // Set the X binning parameters
  this->setSharedX(inSpec->sharedX());
 
  // Manually set that this is sorted by TOF, since it is. This will make it
  // "threadSafe" in other algos.
  this->setSortOrder(TOF_SORT);
}
 
// --------------------------------------------------------------------------
// --- Operators
// -------------------------------------------------------------------
 
EventList &EventList::operator=(const EventList &rhs) {
  // Note that we are NOT copying the MRU pointer
  // the EventWorkspace that possesses the EventList has already configured the mru
  IEventList::operator=(rhs);
  m_histogram = rhs.m_histogram;
  rhs.copyDataInto(*this);
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const Types::Event::TofEvent &event) {
 
  switch (this->eventType) {
  case TOF:
    // Simply push the events
    this->events->emplace_back(event);
    break;
 
  case WEIGHTED:
    this->weightedEvents->emplace_back(event);
    break;
 
  case WEIGHTED_NOTIME:
    this->weightedEventsNoTime->emplace_back(event);
    break;
  }
 
  this->order = UNSORTED;
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const std::vector<Types::Event::TofEvent> &more_events) {
  switch (this->eventType) {
  case TOF:
    // Simply push the events
    this->events->insert(this->events->end(), more_events.cbegin(), more_events.cend());
    break;
 
  case WEIGHTED:
    // Add default weights to all the un-weighted incoming events from the list.
    // and append to the list
    this->weightedEvents->reserve(this->weightedEvents->size() + more_events.size());
    std::copy(more_events.cbegin(), more_events.cend(), std::back_inserter(*this->weightedEvents));
    break;
 
  case WEIGHTED_NOTIME:
    // Add default weights to all the un-weighted incoming events from the list.
    // and append to the list
    this->weightedEventsNoTime->reserve(this->weightedEventsNoTime->size() + more_events.size());
    std::copy(more_events.cbegin(), more_events.cend(), std::back_inserter(*this->weightedEventsNoTime));
    break;
  }
 
  this->order = UNSORTED;
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const WeightedEvent &event) {
  this->switchTo(WEIGHTED);
  this->weightedEvents->emplace_back(event);
  this->order = UNSORTED;
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const std::vector<WeightedEvent> &more_events) {
  switch (this->eventType) {
  case TOF:
    // Need to switch to weighted
    this->switchTo(WEIGHTED);
    // Fall through to the insertion!
 
  case WEIGHTED:
    // Append the two lists
    this->weightedEvents->insert(weightedEvents->end(), more_events.cbegin(), more_events.cend());
    break;
 
  case WEIGHTED_NOTIME:
    // Add default weights to all the un-weighted incoming events from the list.
    // and append to the list
    this->weightedEventsNoTime->reserve(this->weightedEventsNoTime->size() + more_events.size());
    std::copy(more_events.cbegin(), more_events.cend(), std::back_inserter(*this->weightedEventsNoTime));
    break;
  }
 
  this->order = UNSORTED;
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const std::vector<WeightedEventNoTime> &more_events) {
  switch (this->eventType) {
  case TOF:
  case WEIGHTED:
    // Need to switch to weighted with no time
    this->switchTo(WEIGHTED_NOTIME);
    // Fall through to the insertion!
 
  case WEIGHTED_NOTIME:
    // Simple appending of the two lists
    this->weightedEventsNoTime->insert(weightedEventsNoTime->end(), more_events.cbegin(), more_events.cend());
    break;
  }
 
  this->order = UNSORTED;
  return *this;
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator+=(const EventList &more_events) {
  if (!more_events.empty()) {
    // We'll let the += operator for the given vector of event lists handle it
    switch (more_events.getEventType()) {
    case TOF:
      this->operator+=(*more_events.events);
      break;
 
    case WEIGHTED:
      this->operator+=(*more_events.weightedEvents);
      break;
 
    case WEIGHTED_NOTIME:
      this->operator+=(*more_events.weightedEventsNoTime);
      break;
    }
 
    // No guaranteed order
    if (this->empty()) {
      this->order = more_events.order;
    } else {
      this->order = UNSORTED;
    }
  }
 
  // Do a union between the detector IDs of both lists
  addDetectorIDs(more_events.getDetectorIDs());
 
  return *this;
}
 
// --------------------------------------------------------------------------
template <class T1, class T2> void EventList::minusHelper(std::vector<T1> &events, const std::vector<T2> &more_events) {
  // Make the end vector big enough in one go (avoids repeated re-allocations).
  events.reserve(events.size() + more_events.size());
  /* In the event of subtracting in place, calling the end() vector would make
   * it point at the wrong place
   * Using it caused a segault, Ticket #2306.
   * So we cache the end (this speeds up too).
   */
  // We call the constructor for T1. In the case of WeightedEventNoTime, the pulse time will just be ignored.
  std::transform(more_events.cbegin(), more_events.cend(), std::back_inserter(events),
                 [](const auto &ev) { return T1(ev.tof(), ev.pulseTime(), ev.weight() * (-1.0), ev.errorSquared()); });
}
 
// --------------------------------------------------------------------------
EventList &EventList::operator-=(const EventList &more_events) {
  if (this == &more_events) {
    // Special case, ticket #3844 part 2.
    // When doing this = this - this,
    // simply clear the input event list. Saves memory!
    this->clearData();
    return *this;
  }
 
  // We'll let the -= operator for the given vector of event lists handle it
  switch (this->getEventType()) {
  case TOF:
    this->switchTo(WEIGHTED);
    // Fall through
 
  case WEIGHTED:
    switch (more_events.getEventType()) {
    case TOF:
      minusHelper(*this->weightedEvents, *more_events.events);
      break;
    case WEIGHTED:
      minusHelper(*this->weightedEvents, *more_events.weightedEvents);
      break;
    case WEIGHTED_NOTIME:
      // TODO: Should this throw?
      minusHelper(*this->weightedEvents, *more_events.weightedEventsNoTime);
      break;
    }
    break;
 
  case WEIGHTED_NOTIME:
    switch (more_events.getEventType()) {
    case TOF:
      minusHelper(*this->weightedEventsNoTime, *more_events.events);
      break;
    case WEIGHTED:
      minusHelper(*this->weightedEventsNoTime, *more_events.weightedEvents);
      break;
    case WEIGHTED_NOTIME:
      minusHelper(*this->weightedEventsNoTime, *more_events.weightedEventsNoTime);
      break;
    }
    break;
  }
 
  // No guaranteed order
  this->order = UNSORTED;
 
  // NOTE: What to do about detector ID's?
  return *this;
}
 
namespace {
/*
 * Both can be nullptr, or the values can be equal, but do not have one nullptr
 */
template <typename T>
bool vectorPtrEquals(const std::unique_ptr<std::vector<T>> &left, const std::unique_ptr<std::vector<T>> &right) {
  if (left && right) {
    return (*left == *right);
    ;
  } else if ((left && !right) || (right && !left)) {
    return false;
  }
  return true;
}
} // anonymous namespace
 
// --------------------------------------------------------------------------
bool EventList::operator==(const EventList &rhs) const {
  if (this->getNumberEvents() != rhs.getNumberEvents())
    return false;
  if (this->eventType != rhs.eventType)
    return false;
  if (this->empty())
    return true;
  // Check all event lists; The empty ones will compare equal
  if (!vectorPtrEquals(events, rhs.events))
    return false;
  if (!vectorPtrEquals(weightedEvents, rhs.weightedEvents))
    return false;
  if (!vectorPtrEquals(weightedEventsNoTime, rhs.weightedEventsNoTime))
    return false;
 
  // nothing wasn't equal, so they are equal
  return true;
}
 
bool EventList::operator!=(const EventList &rhs) const { return (!this->operator==(rhs)); }
 
bool EventList::equals(const EventList &rhs, const double tolTof, const double tolWeight,
                       const int64_t tolPulse) const {
  // generic checks
  if (this->getNumberEvents() != rhs.getNumberEvents())
    return false;
  if (this->eventType != rhs.eventType)
    return false;
  if (this->empty())
    return true;
 
  // loop over the events
  switch (this->eventType) {
  case TOF: {
    auto leftIter = this->events->cbegin();
    auto leftEnd = this->events->cend();
    auto rightIter = rhs.events->cbegin();
    while (leftIter != leftEnd) {
      if (!leftIter->equals(*rightIter, tolTof, tolPulse))
        return false;
      leftIter = std::next(leftIter);
      rightIter = std::next(rightIter);
    }
    break;
  }
  case WEIGHTED: {
    auto leftIter = this->weightedEvents->cbegin();
    auto leftEnd = this->weightedEvents->cend();
    auto rightIter = rhs.weightedEvents->cbegin();
    while (leftIter != leftEnd) {
      if (!leftIter->equals(*rightIter, tolTof, tolWeight, tolPulse))
        return false;
      leftIter = std::next(leftIter);
      rightIter = std::next(rightIter);
    }
    break;
  }
  case WEIGHTED_NOTIME: {
    auto leftIter = this->weightedEventsNoTime->cbegin();
    auto leftEnd = this->weightedEventsNoTime->cend();
    auto rightIter = rhs.weightedEventsNoTime->cbegin();
    while (leftIter != leftEnd) {
      if (!leftIter->equals(*rightIter, tolTof, tolWeight))
        return false;
      leftIter = std::next(leftIter);
      rightIter = std::next(rightIter);
    }
    break;
  }
  default:
    break;
  }
 
  // anything that gets this far is equal within tolerances
  return true;
}
 
// -----------------------------------------------------------------------------------------------
EventType EventList::getEventType() const { return eventType; }
 
// -----------------------------------------------------------------------------------------------
void EventList::switchTo(EventType newType) {
  switch (newType) {
  case TOF:
    if (eventType != TOF)
      throw std::runtime_error("EventList::switchTo() called on an EventList with weights to go down to TofEvent's. "
                               "This would remove weight information and therefore is not possible.");
    break;
 
  case WEIGHTED:
    switchToWeightedEvents();
    break;
 
  case WEIGHTED_NOTIME:
    switchToWeightedEventsNoTime();
    break;
  }
  // Make sure to free memory
  this->clearUnused();
}
 
// -----------------------------------------------------------------------------------------------
void EventList::switchToWeightedEvents() {
  switch (eventType) {
  case WEIGHTED:
    // Do nothing; it already is weighted
    return;
 
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::switchToWeightedEvents() called on an EventList with WeightedEventNoTime's. "
                             "It has lost the pulse time information and can't go back to WeightedEvent's.");
    break;
 
  case TOF:
    if (events && !events->empty()) {
      // Convert and copy all TofEvents to the weightedEvents list.
      weightedEvents = std::make_unique<std::vector<WeightedEvent>>(events->cbegin(), events->cend());
      // Get rid of the old events
      events.reset();
    } else {
      weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
    }
    eventType = WEIGHTED;
    break;
  }
}
 
// -----------------------------------------------------------------------------------------------
void EventList::switchToWeightedEventsNoTime() {
  switch (eventType) {
  case WEIGHTED_NOTIME:
    // Do nothing if already there
    return;
 
  case TOF: {
    if (events && !events->empty()) {
      // Convert and copy all TofEvents to the weightedEvents list.
      this->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>(events->cbegin(), events->cend());
      // Get rid of the old events
      events.reset();
    } else {
      this->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
    }
    break;
  }
 
  case WEIGHTED: {
    // Convert and copy all TofEvents to the weightedEvents list.
    if (weightedEvents && !weightedEvents->empty()) {
      this->weightedEventsNoTime =
          std::make_unique<std::vector<WeightedEventNoTime>>(weightedEvents->cbegin(), weightedEvents->cend());
      // Get rid of the old events
      weightedEvents.reset();
    } else {
      this->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
    }
    break;
  }
  }
  eventType = WEIGHTED_NOTIME;
}
 
// ==============================================================================================
// --- Testing functions (mostly)
// ---------------------------------------------------------------
// ==============================================================================================
 
WeightedEvent EventList::getEvent(size_t event_number) {
  switch (eventType) {
  case TOF:
    return WeightedEvent(events->at(event_number));
  case WEIGHTED:
    return weightedEvents->at(event_number);
  case WEIGHTED_NOTIME: {
    const auto event = weightedEventsNoTime->at(event_number);
    return WeightedEvent(event.tof(), 0, event.weight(), event.errorSquared());
  }
  }
  throw std::runtime_error("EventList: invalid event type value was found.");
}
 
// ==============================================================================================
// --- Handling the event list
// -------------------------------------------------------------------
// ==============================================================================================
 
const std::vector<TofEvent> &EventList::getEvents() const {
  if (eventType != TOF)
    throw std::runtime_error("EventList::getEvents() called for an EventList that has weights. Use getWeightedEvents() "
                             "or getWeightedEventsNoTime().");
  if (this->events)
    return *this->events;
  else
    throw std::runtime_error("unweighted event vector is not initialized");
}
 
std::vector<TofEvent> &EventList::getEvents() {
  if (eventType != TOF)
    throw std::runtime_error("EventList::getEvents() called for an EventList that has weights. Use getWeightedEvents() "
                             "or getWeightedEventsNoTime().");
  if (this->events)
    return *this->events;
  else
    throw std::runtime_error("unweighted event vector is not initialized");
}
 
std::vector<WeightedEvent> &EventList::getWeightedEvents() {
  if (eventType != WEIGHTED)
    throw std::runtime_error("EventList::getWeightedEvents() called for an EventList not of type WeightedEvent. Use "
                             "getEvents() or getWeightedEventsNoTime().");
  if (this->weightedEvents)
    return *this->weightedEvents;
  else
    throw std::runtime_error("weighted event vector is not initialized");
}
 
const std::vector<WeightedEvent> &EventList::getWeightedEvents() const {
  if (eventType != WEIGHTED)
    throw std::runtime_error("EventList::getWeightedEvents() called for an EventList not of type WeightedEvent. Use "
                             "getEvents() or getWeightedEventsNoTime().");
  if (this->weightedEvents)
    return *this->weightedEvents;
  else
    throw std::runtime_error("weighted event vector is not initialed");
}
 
std::vector<WeightedEventNoTime> &EventList::getWeightedEventsNoTime() {
  if (eventType != WEIGHTED_NOTIME)
    throw std::runtime_error("EventList::getWeightedEventsNoTime() called for an EventList not of type "
                             "WeightedEventNoTime. Use getEvents() or getWeightedEvents().");
  if (this->weightedEventsNoTime)
    return *this->weightedEventsNoTime;
  else
    throw std::runtime_error("weighted event no time vector is not initialed");
}
 
const std::vector<WeightedEventNoTime> &EventList::getWeightedEventsNoTime() const {
  if (eventType != WEIGHTED_NOTIME)
    throw std::runtime_error("EventList::getWeightedEventsNoTime() called for an EventList not of type "
                             "WeightedEventNoTime. Use getEvents() or getWeightedEvents().");
  if (this->weightedEventsNoTime)
    return *this->weightedEventsNoTime;
  else
    throw std::runtime_error("weighted event no time vector is not initialed");
}
 
void EventList::clear(const bool removeDetIDs) {
  if (mru) {
    try {
      mru->deleteIndex(this);
    } catch (const std::runtime_error &) {
      // this is an ignorable error
    }
  }
  // clear representations that aren't for the current type
  this->clearUnused();
 
  // release unused memory or allocate new vector
  // rather than creating a new object, reset existing pointer
  if (!this->empty()) {
    if (this->events && eventType == TOF) {
      this->events->clear();
      std::vector<TofEvent>().swap(*this->events); // STL Trick to release memory
    }
    if (this->weightedEvents && eventType == WEIGHTED) {
      this->weightedEvents->clear();
      std::vector<WeightedEvent>().swap(*this->weightedEvents); // STL Trick to release memory
    }
    if (this->weightedEventsNoTime && eventType == WEIGHTED_NOTIME) {
      this->weightedEventsNoTime->clear();
      std::vector<WeightedEventNoTime>().swap(*this->weightedEventsNoTime); // STL Trick to release memory
    }
  }
  if (removeDetIDs)
    this->clearDetectorIDs();
}
 
void EventList::clearUnused() {
  if (eventType != TOF && (this->events)) {
    this->events.reset();
  }
  if (eventType != WEIGHTED && (this->weightedEvents)) {
    this->weightedEvents.reset();
  }
  if (eventType != WEIGHTED_NOTIME && (this->weightedEventsNoTime)) {
    this->weightedEventsNoTime.reset();
  }
}
 
void EventList::clearData() { this->clear(false); }
 
void EventList::setMRU(EventWorkspaceMRU *newMRU) { mru = newMRU; }
 
void EventList::reserve(size_t num) {
  switch (this->eventType) {
  case TOF:
    this->events->reserve(num);
    break;
  case WEIGHTED:
    this->weightedEvents->reserve(num);
    break;
  case WEIGHTED_NOTIME:
    this->weightedEventsNoTime->reserve(num);
    break;
  }
}
 
// ==============================================================================================
// --- Sorting functions -----------------------------------------------------
// ==============================================================================================
 
// --------------------------------------------------------------------------
void EventList::sort(const EventSortType order) const {
  if (order == UNSORTED) {
    return; // don't bother doing anything. Why did you ask to unsort?
  } else if (order == TOF_SORT) {
    this->sortTof();
  } else if (order == PULSETIME_SORT) {
    this->sortPulseTime();
  } else if (order == PULSETIMETOF_SORT) {
    this->sortPulseTimeTOF();
  } else if (order == PULSETIMETOF_DELTA_SORT) {
    throw std::invalid_argument("sorting by pulse time with delta requires "
                                "extra parameters. Use sortPulseTimeTOFDelta "
                                "instead.");
  } else if (order == TIMEATSAMPLE_SORT) {
    throw std::invalid_argument("sorting by time at sample requires extra "
                                "parameters. Use sortTimeAtSample instead.");
  } else {
    throw runtime_error("Invalid sort type in EventList::sort(EventSortType)");
  }
}
 
// --------------------------------------------------------------------------
void EventList::setSortOrder(const EventSortType order) const { this->order = order; }
 
namespace {
// these are abstractions
template <class RandomIt> void switchable_sort(RandomIt first, RandomIt last) {
  const auto vec_size = static_cast<size_t>(std::distance(first, last));
  if (vec_size < 2)
    return;
  else if (vec_size < MIN_VEC_LENGTH_PARALLEL_SORT)
    std::sort(first, last);
  else
    tbb::parallel_sort(first, last);
}
 
template <class RandomIt, class Compare> void switchable_sort(RandomIt first, RandomIt last, Compare comp) {
  const auto vec_size = static_cast<size_t>(std::distance(first, last));
  if (vec_size < 2)
    return;
  else if (vec_size < MIN_VEC_LENGTH_PARALLEL_SORT)
    std::sort(first, last, std::move(comp));
  else
    tbb::parallel_sort(first, last, comp);
}
} // anonymous namespace
 
// --------------------------------------------------------------------------
void EventList::sortTof() const {
  // nothing to do
  if (this->order == TOF_SORT)
    return;
 
  // Avoid sorting from multiple threads
  std::lock_guard<std::mutex> _lock(m_sortMutex);
  // If the list was sorted while waiting for the lock, return.
  if (this->order == TOF_SORT) // cppcheck-suppress identicalConditionAfterEarlyExit
    return;
 
  switch (eventType) {
  case TOF:
    switchable_sort(events->begin(), events->end());
    break;
  case WEIGHTED:
    switchable_sort(weightedEvents->begin(), weightedEvents->end());
    break;
  case WEIGHTED_NOTIME:
    switchable_sort(weightedEventsNoTime->begin(), weightedEventsNoTime->end());
    break;
  }
  // Save the order to avoid unnecessary re-sorting.
  this->order = TOF_SORT;
}
 
// --------------------------------------------------------------------------
void EventList::sortTimeAtSample(const double &tofFactor, const double &tofShift, bool forceResort) const {
  // Check pre-cached sort flag.
  if (this->order == TIMEATSAMPLE_SORT && !forceResort)
    return;
 
  // Avoid sorting from multiple threads
  std::lock_guard<std::mutex> _lock(m_sortMutex);
  // If the list was sorted while waiting for the lock, return.
  if (this->order == TIMEATSAMPLE_SORT && !forceResort)
    return;
 
  // Perform sort.
  switch (eventType) {
  case TOF: {
    CompareTimeAtSample<TofEvent> comparitor(tofFactor, tofShift);
    switchable_sort(events->begin(), events->end(), comparitor);
  } break;
  case WEIGHTED: {
    CompareTimeAtSample<WeightedEvent> comparitor(tofFactor, tofShift);
    switchable_sort(weightedEvents->begin(), weightedEvents->end(), comparitor);
  } break;
  case WEIGHTED_NOTIME: {
    CompareTimeAtSample<WeightedEventNoTime> comparitor(tofFactor, tofShift);
    switchable_sort(weightedEventsNoTime->begin(), weightedEventsNoTime->end(), comparitor);
  } break;
  }
  // Save the order to avoid unnecessary re-sorting.
  this->order = TIMEATSAMPLE_SORT;
}
 
// --------------------------------------------------------------------------
void EventList::sortPulseTime() const {
  if (this->order == PULSETIME_SORT || this->order == PULSETIMETOF_SORT)
    return; // nothing to do
 
  // Avoid sorting from multiple threads
  std::lock_guard<std::mutex> _lock(m_sortMutex);
  // If the list was sorted while waiting for the lock, return.
  if (this->order == PULSETIME_SORT)
    return;
 
  // Perform sort.
  switch (eventType) {
  case TOF:
    switchable_sort(events->begin(), events->end(), compareEventPulseTime);
    break;
  case WEIGHTED:
    switchable_sort(weightedEvents->begin(), weightedEvents->end(), compareEventPulseTime);
    break;
  case WEIGHTED_NOTIME:
    // Do nothing; there is no time to sort
    break;
  }
  // Save the order to avoid unnecessary re-sorting.
  this->order = PULSETIME_SORT;
}
 
/*
 * Sort events by pulse time + TOF
 * (the absolute time)
 */
void EventList::sortPulseTimeTOF() const {
  if (this->order == PULSETIMETOF_SORT)
    return; // already ordered
 
  // Avoid sorting from multiple threads
  std::lock_guard<std::mutex> _lock(m_sortMutex);
  // If the list was sorted while waiting for the lock, return.
  if (this->order == PULSETIMETOF_SORT) // cppcheck-suppress identicalConditionAfterEarlyExit
    return;
 
  switch (eventType) {
  case TOF:
    switchable_sort(events->begin(), events->end(), compareEventPulseTimeTOF);
    break;
  case WEIGHTED:
    switchable_sort(weightedEvents->begin(), weightedEvents->end(), compareEventPulseTimeTOF);
    break;
  case WEIGHTED_NOTIME:
    // Do nothing; there is no time to sort
    break;
  }
 
  // Save
  this->order = PULSETIMETOF_SORT;
}
 
void EventList::sortPulseTimeTOFDelta(const Types::Core::DateAndTime &start, const double seconds) const {
  // Avoid sorting from multiple threads
  std::lock_guard<std::mutex> _lock(m_sortMutex);
 
  std::function<bool(const TofEvent &, const TofEvent &)> comparator = comparePulseTimeTOFDelta(start, seconds);
 
  switch (eventType) {
  case TOF:
    switchable_sort(events->begin(), events->end(), std::move(comparator));
    break;
  case WEIGHTED:
    switchable_sort(weightedEvents->begin(), weightedEvents->end(), std::move(comparator));
    break;
  case WEIGHTED_NOTIME:
    // Do nothing; there is no time to sort
    break;
  }
 
  this->order = UNSORTED; // so the function always re-runs
}
 
// --------------------------------------------------------------------------
bool EventList::isSortedByTof() const { return (this->order == TOF_SORT); }
 
// --------------------------------------------------------------------------
EventSortType EventList::getSortType() const { return this->order; }
 
// --------------------------------------------------------------------------
void EventList::reverse() {
  // reverse the histogram bin parameters. Changing X invalidates any histogram cached in the MRU,
  // so drop it first -- this is what the deprecated dataX() used to do implicitly.
  if (mru)
    mru->deleteIndex(this);
  auto &x = mutableX();
  std::reverse(x.begin(), x.end());
 
  // flip the events if they are tof sorted
  if (this->isSortedByTof()) {
    switch (eventType) {
    case TOF:
      std::reverse(this->events->begin(), this->events->end());
      break;
    case WEIGHTED:
      std::reverse(this->weightedEvents->begin(), this->weightedEvents->end());
      break;
    case WEIGHTED_NOTIME:
      std::reverse(this->weightedEventsNoTime->begin(), this->weightedEventsNoTime->end());
      break;
    }
    // And we are still sorted! :)
  }
  // Otherwise, do nothing. If it was sorted by pulse time, then it still is
}
 
// --------------------------------------------------------------------------
size_t EventList::getNumberEvents() const {
  switch (eventType) {
  case TOF:
    return (this->events) ? this->events->size() : 0;
  case WEIGHTED:
    return (this->weightedEvents) ? this->weightedEvents->size() : 0;
  case WEIGHTED_NOTIME:
    return (this->weightedEventsNoTime) ? this->weightedEventsNoTime->size() : 0;
  }
  throw std::runtime_error("EventList: invalid event type value was found.");
}
 
bool EventList::empty() const {
  switch (eventType) {
  case TOF:
    if (this->events)
      return this->events->empty();
    else
      throw std::runtime_error("TOF events is nullptr");
  case WEIGHTED:
    if (this->weightedEvents)
      return this->weightedEvents->empty();
    else
      throw std::runtime_error("WEIGHTED events is nullptr");
  case WEIGHTED_NOTIME:
    if (this->weightedEventsNoTime)
      return this->weightedEventsNoTime->empty();
    else
      throw std::runtime_error("WEIGHTED_NOTIME events is nullptr");
  }
  throw std::runtime_error("EventList: invalid event type value was found.");
}
 
// --------------------------------------------------------------------------
size_t EventList::getMemorySize() const {
  switch (eventType) {
  case TOF:
    return this->events->capacity() * sizeof(TofEvent) + sizeof(EventList);
  case WEIGHTED:
    return this->weightedEvents->capacity() * sizeof(WeightedEvent) + sizeof(EventList);
  case WEIGHTED_NOTIME:
    return this->weightedEventsNoTime->capacity() * sizeof(WeightedEventNoTime) + sizeof(EventList);
  }
  throw std::runtime_error("EventList: invalid event type value was found.");
}
 
// --------------------------------------------------------------------------
size_t EventList::histogram_size() const {
  size_t x_size = x().size();
  if (x_size > 1)
    return x_size - 1;
  else
    return 0;
}
 
// ==============================================================================================
// --- Setting the Histogram X axis, without recalculating the histogram
// -----------------------
// ==============================================================================================
 
void EventList::setX(const Kernel::cow_ptr<HistogramData::HistogramX> &X) {
  m_histogram.setSharedX(X);
  if (mru)
    mru->deleteIndex(this);
}
 
MantidVec &EventList::dataX() {
  if (mru)
    mru->deleteIndex(this);
  // Handing out a mutable MantidVec would allow the length to be changed, so
  // FixedLengthVector::mutableRawData() is protected and Histogram is its only friend. The
  // deprecated legacy accessor is therefore the only way to express this.
  GNU_DIAG_OFF("deprecated-declarations")
  MSVC_DIAG_OFF(4996)
  return m_histogram.dataX();
  MSVC_DIAG_ON(4996)
  GNU_DIAG_ON("deprecated-declarations")
}
 
const MantidVec &EventList::dataX() const { return m_histogram.x().rawData(); }
 
const MantidVec &EventList::readX() const { return m_histogram.x().rawData(); }
 
Kernel::cow_ptr<HistogramData::HistogramX> EventList::ptrX() const { return m_histogram.sharedX(); }
 
GNU_DIAG_OFF("deprecated-declarations")
MSVC_DIAG_OFF(4996)
MantidVec &EventList::dataDx() { return m_histogram.dataDx(); }
MSVC_DIAG_ON(4996)
GNU_DIAG_ON("deprecated-declarations")
const MantidVec &EventList::dataDx() const { return m_histogram.dx().rawData(); }
const MantidVec &EventList::readDx() const { return m_histogram.dx().rawData(); }
 
// ==============================================================================================
// --- Return Data Vectors --------------------------------------------------
// ==============================================================================================
 
MantidVec *EventList::makeDataY() const {
  auto Y = new MantidVec();
  MantidVec E;
  // Generate the Y histogram while skipping the E if possible.
  generateHistogram(x().rawData(), *Y, E, true);
  return Y;
}
 
MantidVec *EventList::makeDataE() const {
  MantidVec Y;
  auto E = new MantidVec();
  generateHistogram(x().rawData(), Y, *E);
  // Y is unused.
  return E;
}
 
HistogramData::Histogram EventList::getHistogram() const { return m_histogram; }
 
HistogramData::Histogram EventList::histogram() const {
  HistogramData::Histogram ret(m_histogram);
  ret.setSharedY(sharedY());
  ret.setSharedE(sharedE());
  return ret;
}
 
HistogramData::Counts EventList::counts() const { return histogram().counts(); }
 
HistogramData::CountVariances EventList::countVariances() const { return histogram().countVariances(); }
 
HistogramData::CountStandardDeviations EventList::countStandardDeviations() const {
  return histogram().countStandardDeviations();
}
 
HistogramData::Frequencies EventList::frequencies() const { return histogram().frequencies(); }
 
HistogramData::FrequencyVariances EventList::frequencyVariances() const { return histogram().frequencyVariances(); }
 
HistogramData::FrequencyStandardDeviations EventList::frequencyStandardDeviations() const {
  return histogram().frequencyStandardDeviations();
}
 
const HistogramData::HistogramY &EventList::y() const {
  if (!mru)
    throw std::runtime_error("'EventList::y()' called with no MRU set. This is not allowed.");
 
  return *sharedY();
}
const HistogramData::HistogramE &EventList::e() const {
  if (!mru)
    throw std::runtime_error("'EventList::e()' called with no MRU set. This is not allowed.");
 
  return *sharedE();
}
Kernel::cow_ptr<HistogramData::HistogramY> EventList::sharedY() const {
  // This is the thread number from which this function was called.
  const int thread = PARALLEL_THREAD_NUMBER;
 
  Kernel::cow_ptr<HistogramData::HistogramY> yData(nullptr);
 
  // Is the data in the mrulist?
  if (mru) {
    mru->ensureEnoughBuffersY(static_cast<size_t>(thread));
    yData = mru->findY(static_cast<size_t>(thread), this);
  }
 
  if (!yData) {
    MantidVec Y;
    MantidVec E;
    this->generateHistogram(x().rawData(), Y, E);
 
    // Create the MRU object
    yData = Kernel::make_cow<HistogramData::HistogramY>(std::move(Y));
 
    // Lets save it in the MRU
    if (mru) {
      mru->insertY(thread, yData, this);
      auto eData = Kernel::make_cow<HistogramData::HistogramE>(std::move(E));
      mru->ensureEnoughBuffersE(thread);
      mru->insertE(thread, eData, this);
    }
  }
  return yData;
}
Kernel::cow_ptr<HistogramData::HistogramE> EventList::sharedE() const {
  // This is the thread number from which this function was called.
  const auto thread = static_cast<size_t>(PARALLEL_THREAD_NUMBER);
 
  Kernel::cow_ptr<HistogramData::HistogramE> eData(nullptr);
 
  // Is the data in the mrulist?
  if (mru) {
    mru->ensureEnoughBuffersE(thread);
    eData = mru->findE(thread, this);
  }
 
  if (!eData) {
    // Now use that to get E -- Y values are generated from another function
    MantidVec Y_ignored;
    MantidVec E;
    this->generateHistogram(x().rawData(), Y_ignored, E);
    eData = Kernel::make_cow<HistogramData::HistogramE>(std::move(E));
 
    // Lets save it in the MRU
    if (mru)
      mru->insertE(thread, eData, this);
  }
  return eData;
}
const MantidVec &EventList::dataY() const {
  if (!mru)
    throw std::runtime_error("'EventList::dataY()' called with no MRU set. This is not allowed.");
 
  // WARNING: The Y data of sharedY() is stored in MRU, returning reference fine
  // as long as it stays there.
  return sharedY()->rawData();
}
 
const MantidVec &EventList::dataE() const {
  if (!mru)
    throw std::runtime_error("'EventList::dataE()' called with no MRU set. This is not allowed.");
 
  // WARNING: The E data of sharedE() is stored in MRU, returning reference fine
  // as long as it stays there.
  return sharedE()->rawData();
}
 
namespace {
inline double calcNorm(const double errorSquared) {
  if (errorSquared == 0.)
    return 0;
  else if (errorSquared == 1.)
    return 1.;
  else
    return 1. / std::sqrt(errorSquared);
}
} // namespace
 
// --------------------------------------------------------------------------
template <class T>
inline void EventList::compressEventsHelper(const std::vector<T> &events, std::vector<WeightedEventNoTime> &out,
                                            double tolerance) {
  // Clear the output. We can't know ahead of time how much space to reserve :(
  out.clear();
  // We will make a starting guess of 1/20th of the number of input events.
  out.reserve(events.size() / 20);
 
  // The last TOF to which we are comparing.
  double lastTof = events.front().m_tof;
  // For getting an accurate average TOF
  double totalTof = 0;
  int num = 0;
  // Carrying weight, error, and normalization
  double weight = 0;
  double errorSquared = 0;
  double normalization = 0.;
 
  double bin_end = lastTof;
  std::function<bool(const double, const double)> compareTof;
  std::function<double(const double, double)> next_bin;
 
  if (tolerance < 0) { // log
    if (lastTof < 0)
      throw std::runtime_error("compressEvents with log binning doesn't work with negative TOF");
 
    if (lastTof == 0)
      bin_end = fabs(tolerance);
 
    // for log we do "less than" so that is matches the log binning of the Rebin algorithm
    compareTof = [](const double lhs, const double rhs) { return lhs < rhs; };
    next_bin = [tolerance](const double lastTof, double bin_end) {
      // advance the bin_end until we find the one that this next event falls into
      while (lastTof >= bin_end)
        bin_end = bin_end * (1 - tolerance);
      return bin_end;
    };
  } else { // linear
    // for linear we do "less than or equals" because that is how it was originally implemented
    compareTof = [](const double lhs, const double rhs) { return lhs <= rhs; };
    next_bin = [tolerance](const double lastTof, double) { return lastTof + tolerance; };
  }
 
  // get first bin_end
  bin_end = next_bin(lastTof, bin_end);
 
  for (auto it = events.cbegin(); it != events.cend(); it++) {
    if (compareTof(it->m_tof, bin_end)) {
      // Carry the error and weight
      weight += it->weight();
      errorSquared += it->errorSquared();
      // Track the average tof
      num++;
      const double norm = calcNorm(it->errorSquared());
      normalization += norm;
      totalTof += it->m_tof * norm;
    } else {
      // We exceeded the tolerance
      // Create a new event with the average TOF and summed weights and
      // squared errors.
      if (num == 1) {
        // last time-of-flight is the only one contributing
        out.emplace_back(lastTof, weight, errorSquared);
      } else if (num > 1) {
        out.emplace_back(totalTof / normalization, weight, errorSquared);
      }
      // Start a new combined object
      num = 1;
      const double norm = calcNorm(it->errorSquared());
      normalization = norm;
      totalTof = it->m_tof * norm;
      weight = it->weight();
      errorSquared = it->errorSquared();
      lastTof = it->m_tof;
 
      bin_end = next_bin(lastTof, bin_end);
    }
  }
 
  // Put the last event in there too with the average TOF and summed weights and
  // squared errors.
  if (num == 1) {
    // last time-of-flight is the only one contributing
    out.emplace_back(lastTof, weight, errorSquared);
  } else if (num > 1) {
    out.emplace_back(totalTof / normalization, weight, errorSquared);
  }
 
  // If you have over-allocated by more than 5%, reduce the size.
  size_t excess_limit = out.size() / 20;
  if ((out.capacity() - out.size()) > excess_limit) {
    out.shrink_to_fit();
  }
}
 
template <class T>
inline void EventList::compressFatEventsHelper(const std::vector<T> &events, std::vector<WeightedEvent> &out,
                                               const double tolerance, const Types::Core::DateAndTime &timeStart,
                                               const double seconds) {
  // Clear the output. We can't know ahead of time how much space to reserve :(
  out.clear();
  // We will make a starting guess of 1/20th of the number of input events.
  out.reserve(events.size() / 20);
 
  // The last TOF to which we are comparing.
  double lastTof = events.front().m_tof;
  // For getting an accurate average TOF
  double totalTof = 0;
 
  // pulsetime bin information - stored as int nanoseconds because it
  // is the implementation type for DateAndTime object
  const int64_t pulsetimeStart = timeStart.totalNanoseconds();
  const auto pulsetimeDelta = static_cast<int64_t>(seconds * SEC_TO_NANO);
 
  // pulsetime information
  std::vector<DateAndTime> pulsetimes; // all the times for new event
  std::vector<double> pulsetimeWeights;
 
  // Carrying weight and error
  double weight = 0.;
  double errorSquared = 0.;
  double tofNormalization = 0.;
 
  // Move up to first event that has a large enough pulsetime. This is just in case someone starts from after the
  // starttime of the run. It is expected that users will normally use the default which means this will only check the
  // first event.
  auto it = events.cbegin();
  for (; it != events.cend(); ++it) {
    if (it->m_pulsetime >= timeStart)
      break;
  }
 
  if (it == events.cend())
    throw std::runtime_error("failed to find first pulse time in the events");
 
  // bin if the pulses are histogrammed
  int64_t lastPulseBin = (it->m_pulsetime.totalNanoseconds() - pulsetimeStart) / pulsetimeDelta;
 
  double bin_end = lastTof;
  double tof_min{0};
  std::function<bool(const double, const double)> compareTof;
  std::function<double(const double, double)> next_bin;
 
  if (tolerance < 0) { // log
    // for log we do "less than" so that is matches the log binning of the Rebin algorithm
    compareTof = [](const double lhs, const double rhs) { return lhs < rhs; };
    next_bin = [tolerance](const double lastTof, double bin_end) {
      // advance the bin_end until we find the one that this next event falls into
      while (lastTof >= bin_end)
        bin_end = bin_end * (1 - tolerance);
      return bin_end;
    };
 
    // get minimum Tof so that binning is consistent across all pulses
    const auto event_min = std::min_element(
        events.cbegin(), events.cend(), [](const auto &left, const auto &right) { return left.tof() < right.tof(); });
    bin_end = tof_min = event_min->tof();
 
    if (tof_min < 0)
      throw std::runtime_error("compressEvents with log binning doesn't work with negative TOF");
 
    // can't start at 0 as this will create an infinite loop
    if (tof_min == 0)
      bin_end = tof_min = fabs(tolerance);
 
  } else { // linear
    // for linear we do "less than or equals" because that is how it was originally implemented
    compareTof = [](const double lhs, const double rhs) { return lhs <= rhs; };
    next_bin = [tolerance](const double lastTof, double) { return lastTof + tolerance; };
  }
 
  // get first bin_end
  bin_end = next_bin(lastTof, bin_end);
 
  // loop through events and accumulate weight
  for (; it != events.cend(); ++it) {
    const int64_t eventPulseBin = (it->m_pulsetime.totalNanoseconds() - pulsetimeStart) / pulsetimeDelta;
    if ((eventPulseBin <= lastPulseBin) && compareTof(it->m_tof, bin_end)) {
      // Carry the error and weight
      weight += it->weight();
      errorSquared += it->errorSquared();
      double norm = calcNorm(it->errorSquared());
      tofNormalization += norm;
      // Track the average tof
      totalTof += it->m_tof * norm;
      // Accumulate the pulse times
      pulsetimes.emplace_back(it->m_pulsetime);
      pulsetimeWeights.emplace_back(norm);
    } else {
      // We exceeded the tolerance
      if (!pulsetimes.empty()) {
        // Create a new event with the average TOF and summed weights and
        // squared errors. 1 event used doesn't need to average
        if (pulsetimes.size() == 1) {
          out.emplace_back(lastTof, pulsetimes.front(), weight, errorSquared);
        } else {
          out.emplace_back(totalTof / tofNormalization,
                           Kernel::DateAndTimeHelpers::averageSorted(pulsetimes, pulsetimeWeights), weight,
                           errorSquared);
        }
      }
      if (tolerance < 0 && eventPulseBin != lastPulseBin)
        // reset the bin_end for the new pulse bin
        bin_end = tof_min;
 
      // Start a new combined object
      double norm = calcNorm(it->errorSquared());
      totalTof = it->m_tof * norm;
      weight = it->weight();
      errorSquared = it->errorSquared();
      tofNormalization = norm;
      lastTof = it->m_tof;
      lastPulseBin = eventPulseBin;
      pulsetimes.clear();
      pulsetimes.emplace_back(it->m_pulsetime);
      pulsetimeWeights.clear();
      pulsetimeWeights.emplace_back(norm);
 
      bin_end = next_bin(lastTof, bin_end);
    }
  }
 
  // Put the last event in there too.
  if (!pulsetimes.empty()) {
    // Create a new event with the average TOF and summed weights and
    // squared errors. 1 event used doesn't need to average
    if (pulsetimes.size() == 1) {
      out.emplace_back(lastTof, pulsetimes.front(), weight, errorSquared);
    } else {
      out.emplace_back(totalTof / tofNormalization,
                       Kernel::DateAndTimeHelpers::averageSorted(pulsetimes, pulsetimeWeights), weight, errorSquared);
    }
  }
 
  // If you have over-allocated by more than 5%, reduce the size.
  size_t excess_limit = out.size() / 20;
  if ((out.capacity() - out.size()) > excess_limit) {
    out.shrink_to_fit();
  }
}
 
// --------------------------------------------------------------------------
void EventList::compressEvents(double tolerance, EventList *destination) {
  if (this->empty()) {
    // allocate memory in correct vector
    if (eventType != WEIGHTED_NOTIME)
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
  } else {
    this->sortTof();
    switch (eventType) {
    case TOF:
      //      if (parallel)
      //        compressEventsParallelHelper(this->events,
      //        destination->weightedEventsNoTime, tolerance);
      //      else
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
      compressEventsHelper(*this->events, *destination->weightedEventsNoTime, tolerance);
      break;
 
    case WEIGHTED:
      //      if (parallel)
      //        compressEventsParallelHelper(this->weightedEvents,
      //        destination->weightedEventsNoTime, tolerance);
      //      else
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
      compressEventsHelper(*this->weightedEvents, *destination->weightedEventsNoTime, tolerance);
 
      break;
 
    case WEIGHTED_NOTIME:
      if (destination == this) {
        // Put results in a temp output
        auto out = std::make_unique<std::vector<WeightedEventNoTime>>();
        //        if (parallel)
        //          compressEventsParallelHelper(this->weightedEventsNoTime,
        //          out,
        //          tolerance);
        //        else
        compressEventsHelper(*this->weightedEventsNoTime, *out, tolerance);
        // Put it back
        this->weightedEventsNoTime.swap(out);
      } else {
        //        if (parallel)
        //          compressEventsParallelHelper(this->weightedEventsNoTime,
        //          destination->weightedEventsNoTime, tolerance);
        //        else
        destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
        compressEventsHelper(*this->weightedEventsNoTime, *destination->weightedEventsNoTime, tolerance);
      }
      break;
    }
  }
  // In all cases, you end up WEIGHTED_NOTIME.
  destination->eventType = WEIGHTED_NOTIME;
  // The sort is still valid!
  destination->order = TOF_SORT;
  // Empty out storage for vectors that are now unused.
  destination->clearUnused();
}
 
template <class T>
inline void EventList::createWeightedEvents(std::vector<WeightedEventNoTime> &out, const std::vector<double> &tof,
                                            const std::vector<T> &weight, const std::vector<T> &error) {
  out.clear();
  for (size_t i = 0; i < weight.size(); ++i) {
    const auto errors = static_cast<float>(error[i]);
    if (errors > 0)
      out.emplace_back(tof[i], static_cast<float>(weight[i]), errors);
  }
}
 
template <class T>
inline void EventList::processWeightedEvents(const std::vector<T> &events, std::vector<WeightedEventNoTime> &out,
                                             const std::shared_ptr<std::vector<double>> histogram_bin_edges,
                                             struct FindBin findBin) {
  const auto NUM_BINS = histogram_bin_edges->size() - 1;
  std::vector<double> tof(NUM_BINS, 0.);
  std::vector<double> normalization(NUM_BINS, 0.);
  std::vector<float> weight(NUM_BINS, 0.);
  std::vector<float> error(NUM_BINS, 0.);
  for (const auto &ev : events) {
    const auto &bin_optional = findBin(*histogram_bin_edges.get(), ev.m_tof, false);
    if (bin_optional) {
      const auto bin = bin_optional.value();
      const double norm = calcNorm(ev.m_errorSquared);
      tof[bin] += ev.m_tof * norm;
      normalization[bin] += norm;
      weight[bin] += ev.m_weight;
      error[bin] += ev.m_errorSquared;
    }
  }
 
  // normalize TOFs
  std::transform(tof.begin(), tof.end(), normalization.begin(), tof.begin(), std::divides<double>());
 
  createWeightedEvents(out, tof, weight, error);
}
 
void EventList::compressEvents(double tolerance, EventList *destination,
                               const std::shared_ptr<std::vector<double>> histogram_bin_edges) {
  if (this->empty()) {
    // allocate memory in correct vector
    if (eventType != WEIGHTED_NOTIME)
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
  } else {
    const auto NUM_BINS = histogram_bin_edges->size() - 1;
    const auto xmin = static_cast<double>(histogram_bin_edges->front());
 
    auto findBin = FindBin(tolerance, xmin);
 
    switch (eventType) {
    case TOF: {
      std::vector<double> tof(NUM_BINS, 0);
      std::vector<uint32_t> count(NUM_BINS, 0);
      for (const auto &ev : *this->events) {
        const auto &bin_optional = findBin(*histogram_bin_edges.get(), ev.m_tof, false);
        if (bin_optional) {
          const auto bin = bin_optional.value();
          count[bin]++;
          tof[bin] += ev.m_tof;
        }
      }
 
      // average TOFs
      std::transform(tof.begin(), tof.end(), count.begin(), tof.begin(), std::divides<double>());
 
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
      createWeightedEvents(*destination->weightedEventsNoTime, tof, count, count);
      break;
    }
 
    case WEIGHTED: {
      destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
      processWeightedEvents(*this->weightedEvents, *destination->weightedEventsNoTime, histogram_bin_edges, findBin);
      break;
    }
    case WEIGHTED_NOTIME:
      if (destination == this) {
        // Put results in a temp output
        auto out = std::make_unique<std::vector<WeightedEventNoTime>>();
        processWeightedEvents(*this->weightedEventsNoTime, *out, histogram_bin_edges, findBin);
        // Put it back
        this->weightedEventsNoTime.swap(out);
      } else {
        destination->weightedEventsNoTime = std::make_unique<std::vector<WeightedEventNoTime>>();
        processWeightedEvents(*this->weightedEventsNoTime, *destination->weightedEventsNoTime, histogram_bin_edges,
                              findBin);
      }
      break;
    }
  }
 
  // In all cases, you end up WEIGHTED_NOTIME.
  destination->eventType = WEIGHTED_NOTIME;
  // The result will be sorted
  destination->order = TOF_SORT;
  // Empty out storage for vectors that are now unused.
  destination->clearUnused();
}
 
void EventList::compressFatEvents(const double tolerance, const Mantid::Types::Core::DateAndTime &timeStart,
                                  const double seconds, EventList *destination) {
  if (this->empty()) {
    // allocate memory in correct vector
    if (eventType != WEIGHTED)
      destination->weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
  } else {
    switch (eventType) {
    case WEIGHTED_NOTIME:
      throw std::invalid_argument("Cannot compress events that do not have pulsetime");
    case TOF:
      this->sortPulseTimeTOFDelta(timeStart, seconds);
      destination->weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
      compressFatEventsHelper(*this->events, *destination->weightedEvents, tolerance, timeStart, seconds);
      break;
    case WEIGHTED:
      this->sortPulseTimeTOFDelta(timeStart, seconds);
      if (destination == this) {
        // Put results in a temp output
        auto out = std::make_unique<std::vector<WeightedEvent>>();
        compressFatEventsHelper(*this->weightedEvents, *out, tolerance, timeStart, seconds);
        // Put it back
        this->weightedEvents.swap(out);
      } else {
        destination->weightedEvents = std::make_unique<std::vector<WeightedEvent>>();
        compressFatEventsHelper(*this->weightedEvents, *destination->weightedEvents, tolerance, timeStart, seconds);
      }
      break;
    }
  }
  // In all cases, you end up WEIGHTED_NOTIME.
  destination->eventType = WEIGHTED;
  // The sort order is pulsetimetof as we've compressed out the tolerance
  destination->order = PULSETIMETOF_SORT;
  // Empty out storage for vectors that are now unused.
  destination->clearUnused();
}
 
// --------------------------------------------------------------------------
template <class T>
typename std::vector<T>::const_iterator static findFirstEvent(const std::vector<T> &events, T seek_tof) {
  return std::find_if_not(events.cbegin(), events.cend(), [seek_tof](const T &x) { return x < seek_tof; });
}
 
// --------------------------------------------------------------------------
template <class T>
typename std::vector<T>::const_iterator EventList::findFirstPulseEvent(const std::vector<T> &events,
                                                                       const double seek_pulsetime) {
  auto itev = events.cbegin();
  auto itev_end = events.cend(); // cache for speed
 
  // if tof < X[0], that means that you need to skip some events
  while ((itev != itev_end) && (static_cast<double>(itev->pulseTime().totalNanoseconds()) < seek_pulsetime))
    itev++;
  // Better fix would be to use a binary search instead of the linear one used
  // here.
  return itev;
}
 
// --------------------------------------------------------------------------
template <class T>
typename std::vector<T>::const_iterator
EventList::findFirstTimeAtSampleEvent(const std::vector<T> &events, const double seek_time, const double &tofFactor,
                                      const double &tofOffset) const {
  auto itev = events.cbegin();
  auto itev_end = events.cend(); // cache for speed
 
  // if tof < X[0], that means that you need to skip some events
  while ((itev != itev_end) &&
         (static_cast<double>(calculateCorrectedFullTime(*itev, tofFactor, tofOffset)) < seek_time))
    itev++;
  // Better fix would be to use a binary search instead of the linear one used
  // here.
  return itev;
}
 
// --------------------------------------------------------------------------
template <class T> typename std::vector<T>::iterator static findFirstEvent(std::vector<T> &events, T seek_tof) {
  return std::find_if_not(events.begin(), events.end(), [seek_tof](const T &x) { return x < seek_tof; });
}
 
// --------------------------------------------------------------------------
template <class T>
void EventList::histogramForWeightsHelper(const std::vector<T> &events, std::span<double const> X, MantidVec &Y,
                                          MantidVec &E) {
  // For slight speed=up.
  size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // If the sizes are the same, then the "resize" command will NOT clear the original values.
  bool mustFill = (Y.size() == x_size - 1);
  // Clear the Y data, assign all to 0.
  Y.resize(x_size - 1, 0.0);
  // Clear the Error data, assign all to 0.
  // Note: Errors will be squared until the last step.
  E.resize(x_size - 1, 0.0);
 
  if (mustFill) {
    // We must make sure the starting point is 0.0
    std::fill(Y.begin(), Y.end(), 0.0);
    std::fill(E.begin(), E.end(), 0.0);
  }
 
  //---------------------- Histogram without weights
  //---------------------------------
 
  // Do we even have any events to do?
  if (!events.empty()) {
    // Iterate through all events (sorted by tof)
    auto itev = findFirstEvent(events, T(X[0]));
    auto itev_end = events.cend();
    // The above can still take you to end() if no events above X[0], so check
    // again.
    if (itev == itev_end)
      return;
 
    // Find the first bin
    size_t bin = 0;
    // The tof is greater the first bin boundary, so we need to find the first
    // bin
    double tof = itev->tof();
    while (bin < x_size - 1) {
      // Within range?
      if ((tof >= X[bin]) && (tof < X[bin + 1])) {
        // Add up the weight (convert to double before adding, to preserve
        // precision)
        Y[bin] += double(itev->m_weight);
        E[bin] += double(itev->m_errorSquared); // square of error
        break;
      }
      ++bin;
    }
    // Go to the next event, we've already binned this first one.
    ++itev;
 
    // Keep going through all the events
    while ((itev != itev_end) && (bin < x_size - 1)) {
      tof = itev->tof();
      while (bin < x_size - 1) {
        // Within range? Since both events and X are sorted, they are going to
        // have
        // tof >= X[bin] because the previous event was.
        if (tof < X[bin + 1]) {
          // Add up the weight (convert to double before adding, to preserve
          // precision)
          Y[bin] += double(itev->m_weight);
          E[bin] += double(itev->m_errorSquared); // square of error
          break;
        }
        ++bin;
      }
      ++itev;
    }
  } // end if (there are any events to histogram)
 
  // Now do the sqrt of all errors
  std::transform(E.cbegin(), E.cend(), E.begin(), static_cast<double (*)(double)>(sqrt));
}
 
// --------------------------------------------------------------------------
template <class T>
void EventList::histogramForWeightsHelper(const std::vector<T> &events, const double step, std::span<double const> X,
                                          MantidVec &Y, MantidVec &E) {
  size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // If the sizes are the same, then the "resize" command will NOT clear the original values.
  bool mustFill = (Y.size() == x_size - 1);
  Y.resize(x_size - 1, 0.0);
  E.resize(x_size - 1, 0.0);
  if (mustFill) {
    // We must make sure the starting point is 0.0
    std::fill(Y.begin(), Y.end(), 0.0);
    std::fill(E.begin(), E.end(), 0.0);
  }
 
  if (events.empty())
    return;
 
  const auto xmin = X.front();
  const auto xmax = X.back();
 
  auto findBin = FindBin(step, xmin);
 
  for (const T &ev : events) {
    const double tof = ev.tof();
    if (tof < xmin || tof >= xmax)
      continue;
 
    std::optional<size_t> n_bin = findBin(X, tof, true);
 
    if (n_bin) {
      Y[n_bin.value()] += ev.weight();
      E[n_bin.value()] += ev.errorSquared();
    }
  }
 
  // Now do the sqrt of all errors
  std::transform(E.cbegin(), E.cend(), E.begin(), static_cast<double (*)(double)>(sqrt));
}
 
// --------------------------------------------------------------------------
void EventList::generateHistogramPulseTime(std::span<double const> X, MantidVec &Y, MantidVec &E,
                                           bool skipError) const {
  // All types of weights need to be sorted by Pulse Time
  this->sortPulseTime();
 
  switch (eventType) {
  case TOF:
    // Make the single ones
    this->generateCountsHistogramPulseTime(X, Y);
    if (!skipError)
      this->generateErrorsHistogram(Y, E);
    break;
 
  case WEIGHTED:
    throw std::runtime_error("Cannot histogram by pulse time on Weighted "
                             "Events currently"); // This could be supported.
 
  case WEIGHTED_NOTIME:
    throw std::runtime_error("Cannot histogram by pulse time on Weighted Events NoTime");
  }
}
 
void EventList::generateHistogramTimeAtSample(std::span<double const> X, MantidVec &Y, MantidVec &E,
                                              const double &tofFactor, const double &tofOffset, bool skipError) const {
  // All types of weights need to be sorted by time at sample
  this->sortTimeAtSample(tofFactor, tofOffset);
 
  switch (eventType) {
  case TOF:
    // Make the single ones
    this->generateCountsHistogramTimeAtSample(X, Y, tofFactor, tofOffset);
    if (!skipError)
      this->generateErrorsHistogram(Y, E);
    break;
 
  case WEIGHTED:
    throw std::runtime_error("Cannot histogram by time at sample on Weighted "
                             "Events currently"); // This could be supported.
 
  case WEIGHTED_NOTIME:
    throw std::runtime_error("Cannot histogram by time at sample on Weighted Events NoTime");
  }
}
 
// --------------------------------------------------------------------------
void EventList::generateHistogram(std::span<double const> X, MantidVec &Y, MantidVec &E, bool skipError) const {
  // All types of weights need to be sorted by TOF
 
  this->sortTof();
 
  switch (eventType) {
  case TOF:
    // Make the single ones
    this->generateCountsHistogram(X, Y);
    if (!skipError)
      this->generateErrorsHistogram(Y, E);
    break;
 
  case WEIGHTED:
    histogramForWeightsHelper(*this->weightedEvents, X, Y, E);
    break;
 
  case WEIGHTED_NOTIME:
    histogramForWeightsHelper(*this->weightedEventsNoTime, X, Y, E);
    break;
  }
}
 
// --------------------------------------------------------------------------
void EventList::generateHistogram(const double step, std::span<double const> X, MantidVec &Y, MantidVec &E,
                                  bool skipError) const {
  // if events are already sorted, use faster sorted histogram method
  if (isSortedByTof() || empty())
    return generateHistogram(X, Y, E, skipError);
 
  switch (eventType) {
  case TOF:
    this->generateCountsHistogram(step, X, Y);
    if (!skipError)
      this->generateErrorsHistogram(Y, E);
    break;
 
  case WEIGHTED:
    histogramForWeightsHelper(*this->weightedEvents, step, X, Y, E);
    break;
 
  case WEIGHTED_NOTIME:
    histogramForWeightsHelper(*this->weightedEventsNoTime, step, X, Y, E);
    break;
  }
}
 
// --------------------------------------------------------------------------
void EventList::generateCountsHistogramPulseTime(std::span<double const> X, MantidVec &Y) const {
  // For slight speed=up.
  size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // Sort the events by pulsetime
  this->sortPulseTime();
  // Clear the Y data, assign all to 0.
  Y.resize(x_size - 1, 0);
 
  //---------------------- Histogram without weights
  //---------------------------------
 
  if (!this->events->empty()) {
    // Iterate through all events (sorted by pulse time)
    auto itev = findFirstPulseEvent(*this->events, X[0]);
    auto itev_end = events->cend(); // cache for speed
    // The above can still take you to end() if no events above X[0], so check
    // again.
    if (itev == itev_end)
      return;
 
    // Find the first bin
    size_t bin = 0;
 
    // The tof is greater the first bin boundary, so we need to find the first
    // bin
    double pulsetime = static_cast<double>(itev->pulseTime().totalNanoseconds());
    while (bin < x_size - 1) {
      // Within range?
      if ((pulsetime >= X[bin]) && (pulsetime < X[bin + 1])) {
        Y[bin]++;
        break;
      }
      ++bin;
    }
    // Go to the next event, we've already binned this first one.
    ++itev;
 
    // Keep going through all the events
    while ((itev != itev_end) && (bin < x_size - 1)) {
      pulsetime = static_cast<double>(itev->pulseTime().totalNanoseconds());
      while (bin < x_size - 1) {
        // Within range?
        if ((pulsetime >= X[bin]) && (pulsetime < X[bin + 1])) {
          Y[bin]++;
          break;
        }
        ++bin;
      }
      ++itev;
    }
  } // end if (there are any events to histogram)
}
 
void EventList::generateCountsHistogramPulseTime(const double &xMin, const double &xMax, MantidVec &Y,
                                                 const double TOF_min, const double TOF_max) const {
 
  if (this->events->empty())
    return;
 
  size_t nBins = Y.size();
 
  if (nBins == 0)
    return;
 
  double step = (xMax - xMin) / static_cast<double>(nBins);
 
  for (const TofEvent &ev : *this->events) {
    double pulsetime = static_cast<double>(ev.pulseTime().totalNanoseconds());
    if (pulsetime < xMin || pulsetime >= xMax)
      continue;
    if (ev.tof() < TOF_min || ev.tof() >= TOF_max)
      continue;
 
    auto n_bin = static_cast<size_t>((pulsetime - xMin) / step);
    Y[n_bin]++;
  }
}
 
// --------------------------------------------------------------------------
void EventList::generateCountsHistogramTimeAtSample(std::span<double const> X, MantidVec &Y, const double &tofFactor,
                                                    const double &tofOffset) const {
  // For slight speed=up.
  const size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // Sort the events by pulsetime
  this->sortTimeAtSample(tofFactor, tofOffset);
  // Clear the Y data, assign all to 0.
  Y.resize(x_size - 1, 0);
 
  //---------------------- Histogram without weights
  //---------------------------------
 
  if (!this->events->empty()) {
    // Iterate through all events (sorted by pulse time)
    auto itev = findFirstTimeAtSampleEvent(*this->events, X[0], tofFactor, tofOffset);
    std::vector<TofEvent>::const_iterator itev_end = events->end(); // cache for speed
    // The above can still take you to end() if no events above X[0], so check
    // again.
    if (itev == itev_end)
      return;
 
    // Find the first bin
    size_t bin = 0;
 
    auto tAtSample = static_cast<double>(calculateCorrectedFullTime(*itev, tofFactor, tofOffset));
    while (bin < x_size - 1) {
      // Within range?
      if ((tAtSample >= X[bin]) && (tAtSample < X[bin + 1])) {
        Y[bin]++;
        break;
      }
      ++bin;
    }
    // Go to the next event, we've already binned this first one.
    ++itev;
 
    // Keep going through all the events
    while ((itev != itev_end) && (bin < x_size - 1)) {
      tAtSample = static_cast<double>(calculateCorrectedFullTime(*itev, tofFactor, tofOffset));
      while (bin < x_size - 1) {
        // Within range?
        if ((tAtSample >= X[bin]) && (tAtSample < X[bin + 1])) {
          Y[bin]++;
          break;
        }
        ++bin;
      }
      ++itev;
    }
  } // end if (there are any events to histogram)
}
 
// --------------------------------------------------------------------------
void EventList::generateCountsHistogram(std::span<double const> X, MantidVec &Y) const {
  // For slight speed=up.
  size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // Sort the events by tof
  this->sortTof();
  // Clear the Y data, assign all to 0.
  Y.resize(x_size - 1, 0);
 
  //---------------------- Histogram without weights
  //---------------------------------
 
  // Do we even have any events to do?
  if (!this->events->empty()) {
    // Iterate through all events (sorted by tof) placing them in the correct
    // bin.
    auto itev = findFirstEvent(*this->events, TofEvent(X[0]));
    const auto itend = this->events->end();
    // Go through all the events,
    for (auto itx = X.begin(); itev != itend; ++itev) {
      const double tof = itev->tof();
      itx = std::find_if(itx, X.end(), [tof](const double x) { return tof < x; });
      if (itx == X.end()) {
        break;
      }
      const auto bin = static_cast<size_t>(std::max(std::distance(X.begin(), itx) - 1, std::ptrdiff_t{0}));
      ++Y[bin];
    }
  } // end if (there are any events to histogram)
}
 
std::optional<size_t> EventList::findLinearBin(std::span<double const> X, const double tof, const double divisor,
                                               const double offset, const bool findExact) {
  const auto bin = static_cast<size_t>(tof * divisor - offset);
  if (bin >= X.size())
    return std::nullopt;
  else if (findExact)
    return findExactBin(X, tof, bin);
  else
    return bin;
}
 
std::optional<size_t> EventList::findLogBin(std::span<double const> X, const double tof, const double divisor,
                                            const double offset, const bool findExact) {
  const auto bin = static_cast<size_t>(log(tof) * divisor - offset);
  if (bin >= X.size())
    return std::nullopt;
  else if (findExact)
    return findExactBin(X, tof, bin);
  else
    return bin;
}
 
size_t EventList::findExactBin(std::span<double const> X, const double tof, const size_t n_bin) {
  // is tof slower than suggested bin
  auto tof_of_bin = X.begin() + n_bin; // boundary suggested
  if (tof < *tof_of_bin)
    return std::move(n_bin - 1);
 
  // is tof higher than suggested bin
  ++tof_of_bin; // move to next boundary
  if (tof >= *tof_of_bin)
    return std::move(n_bin + 1);
 
  // tof is in the bin
  return std::move(n_bin);
}
 
// --------------------------------------------------------------------------
void EventList::generateCountsHistogram(const double step, std::span<double const> X, MantidVec &Y) const {
  // For slight speed=up.
  size_t x_size = X.size();
 
  if (x_size <= 1) {
    // X was not set. Return an empty array.
    Y.resize(0, 0);
    return;
  }
 
  // If the sizes are the same, then the "resize" command will NOT clear the original values.
  bool mustFill = (Y.size() == x_size - 1);
  // Clear the Y data, assign all to 0.
  Y.resize(x_size - 1, 0);
  if (mustFill) // starting point is no counts
    std::fill(Y.begin(), Y.end(), 0.0);
 
  // Do we even have any events to do?
  if (this->events->empty())
    return;
 
  const auto xmin = X.front();
  const auto xmax = X.back();
 
  auto findBin = FindBin(step, xmin);
 
  for (const TofEvent &ev : *this->events) {
    const double tof = ev.tof();
    if (tof < xmin || tof >= xmax)
      continue;
 
    const std::optional<size_t> n_bin = findBin(X, tof, true);
 
    if (n_bin)
      Y[n_bin.value()]++;
  }
}
 
// --------------------------------------------------------------------------
void EventList::generateErrorsHistogram(std::span<double const> Y, MantidVec &E) const {
  // Fill the vector for the errors, containing sqrt(count)
  E.resize(Y.size(), 0);
 
  // windows can get confused about std::sqrt
  std::transform(Y.begin(), Y.end(), E.begin(), static_cast<double (*)(double)>(sqrt));
 
} //----------------------------------------------------------------------------------
 
template <class T>
void EventList::integrateHelper(std::vector<T> &events, const double minX, const double maxX, const bool entireRange,
                                double &sum, double &error) {
  sum = 0;
  error = 0;
  // Nothing in the list?
  if (events.empty())
    return;
 
  // Iterators for limits - whole range by default
  auto lowit = events.cbegin();
  auto highit = events.cend();
 
  // But maybe we don't want the entire range?
  if (!entireRange) {
    // If a silly range was given, return 0.
    if (maxX < minX)
      return;
 
    // If the first element is lower that the xmin then search for new lowit
    if (lowit->tof() < minX)
      lowit = std::lower_bound(events.cbegin(), events.cend(), minX);
    // If the last element is higher that the xmax then search for new lowit
    if ((highit - 1)->tof() > maxX) {
      highit = std::upper_bound(lowit, events.cend(), T(maxX));
    }
  }
 
  // Sum up all the weights
  for (auto it = lowit; it != highit; ++it) {
    sum += it->weight();
    error += it->errorSquared();
  }
  error = std::sqrt(error);
}
 
// --------------------------------------------------------------------------
double EventList::integrate(const double minX, const double maxX, const bool entireRange) const {
  double sum(0), error(0);
  integrate(minX, maxX, entireRange, sum, error);
  return sum;
}
 
void EventList::integrate(const double minX, const double maxX, const bool entireRange, double &sum,
                          double &error) const {
  sum = 0;
  error = 0;
  if (!entireRange) {
    // The event list must be sorted by TOF!
    this->sortTof();
  }
 
  // Convert the list
  switch (eventType) {
  case TOF:
    integrateHelper(*this->events, minX, maxX, entireRange, sum, error);
    break;
  case WEIGHTED:
    integrateHelper(*this->weightedEvents, minX, maxX, entireRange, sum, error);
    break;
  case WEIGHTED_NOTIME:
    integrateHelper(*this->weightedEventsNoTime, minX, maxX, entireRange, sum, error);
    break;
  default:
    throw std::runtime_error("EventList: invalid event type value was found.");
  }
}
 
// ==============================================================================================
// ----------- Conversion Functions (changing tof values)
// ---------------------------------------
// ==============================================================================================
 
void EventList::convertTof(std::function<double(double)> func, const int sorting) {
  // fix the histogram parameter. Changing X invalidates any histogram cached in the MRU, so drop
  // it first -- this is what the deprecated dataX() used to do implicitly.
  if (mru)
    mru->deleteIndex(this);
  auto &x = mutableX();
  transform(x.cbegin(), x.cend(), x.begin(), func);
 
  // do nothing if sorting > 0
  if (sorting == 0) {
    this->setSortOrder(UNSORTED);
  } else if ((sorting < 0) && (this->getSortType() == TOF_SORT)) {
    this->reverse();
  }
 
  if (this->getNumberEvents() == 0)
    return;
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->convertTofHelper(*this->events, func);
    break;
  case WEIGHTED:
    this->convertTofHelper(*this->weightedEvents, func);
    break;
  case WEIGHTED_NOTIME:
    this->convertTofHelper(*this->weightedEventsNoTime, func);
    break;
  }
}
 
template <class T> void EventList::convertTofHelper(std::vector<T> &events, const std::function<double(double)> &func) {
  // iterate through all events
  for (auto &ev : events)
    ev.m_tof = func(ev.m_tof);
}
 
// --------------------------------------------------------------------------
void EventList::convertTof(const double factor, const double offset) {
  // fix the histogram parameter
  auto &x = mutableX();
  x *= factor;
  x += offset;
 
  if ((factor < 0.) && (this->getSortType() == TOF_SORT))
    this->reverse();
 
  if (this->getNumberEvents() == 0)
    return;
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->convertTofHelper(*this->events, factor, offset);
    break;
  case WEIGHTED:
    this->convertTofHelper(*this->weightedEvents, factor, offset);
    break;
  case WEIGHTED_NOTIME:
    this->convertTofHelper(*this->weightedEventsNoTime, factor, offset);
    break;
  }
}
 
// --------------------------------------------------------------------------
template <class T> void EventList::convertTofHelper(std::vector<T> &events, const double factor, const double offset) {
  // iterate through all events
  for (auto &event : events) {
    event.m_tof = event.m_tof * factor + offset;
  }
}
 
// --------------------------------------------------------------------------
void EventList::scaleTof(const double factor) { this->convertTof(factor, 0.0); }
 
// --------------------------------------------------------------------------
void EventList::addTof(const double offset) { this->convertTof(1.0, offset); }
 
// --------------------------------------------------------------------------
template <class T> void EventList::addPulsetimeHelper(std::vector<T> &events, const double seconds) {
  // iterate through all events
  for (auto &event : events) {
    event.m_pulsetime += seconds;
  }
}
 
template <class T> void EventList::addPulsetimesHelper(std::vector<T> &events, const std::vector<double> &seconds) {
  auto eventIterEnd{events.end()};
  auto secondsIter{seconds.cbegin()};
  for (auto eventIter = events.begin(); eventIter < eventIterEnd; ++eventIter, ++secondsIter) {
    eventIter->m_pulsetime += *secondsIter;
  }
}
 
// --------------------------------------------------------------------------
void EventList::addPulsetime(const double seconds) {
  if (this->getNumberEvents() == 0)
    return;
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->addPulsetimeHelper(*this->events, seconds);
    break;
  case WEIGHTED:
    this->addPulsetimeHelper(*this->weightedEvents, seconds);
    break;
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::addPulsetime() called on an event "
                             "list with no pulse times. You must call this "
                             "algorithm BEFORE CompressEvents.");
    break;
  }
}
 
// --------------------------------------------------------------------------
void EventList::addPulsetimes(const std::vector<double> &seconds) {
  if (this->getNumberEvents() == 0)
    return;
  if (this->getNumberEvents() != seconds.size()) {
    throw std::runtime_error("");
  }
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->addPulsetimesHelper(*this->events, seconds);
    break;
  case WEIGHTED:
    this->addPulsetimesHelper(*this->weightedEvents, seconds);
    break;
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::addPulsetime() called on an event "
                             "list with no pulse times. You must call this "
                             "algorithm BEFORE CompressEvents.");
    break;
  }
}
 
// --------------------------------------------------------------------------
template <class T>
std::size_t EventList::maskTofHelper(std::vector<T> &events, const double tofMin, const double tofMax) {
  // quick checks to make sure that the masking range is even in the data
  if (tofMin > events.crbegin()->tof())
    return 0;
  if (tofMax < events.cbegin()->tof())
    return 0;
 
  // Find the index of the first tofMin
  auto it_first = std::lower_bound(events.begin(), events.end(), tofMin);
  if ((it_first != events.end()) && (it_first->tof() < tofMax)) {
    // Something was found
    // Look for the first one > tofMax
    auto it_last = std::upper_bound(it_first, events.end(), T(tofMax));
 
    if (it_first >= it_last) {
      throw std::runtime_error("Event filter is all messed up"); // TODO
    }
 
    size_t tmp = std::size_t(std::distance(it_first, it_last));
    // it_last will either be at the end (if not found) or before it.
    // Erase this range from the vector
    events.erase(it_first, it_last);
 
    // Done! Sorting is still valid, no need to redo.
    return tmp; //(it_last - it_first); the iterators get invalid after erase
  }
  return 0; // didn't remove any events
}
 
// --------------------------------------------------------------------------
void EventList::maskTof(const double tofMin, const double tofMax) {
  if (tofMax <= tofMin)
    throw std::runtime_error("EventList::maskTof: tofMax must be > tofMin");
 
  // don't do anything with an emply list
  if (this->getNumberEvents() == 0)
    return;
 
  // Start by sorting by tof
  this->sortTof();
 
  // Convert the list
  size_t numOrig = 0;
  size_t numDel = 0;
  switch (eventType) {
  case TOF:
    numOrig = this->events->size();
    numDel = this->maskTofHelper(*this->events, tofMin, tofMax);
    break;
  case WEIGHTED:
    numOrig = this->weightedEvents->size();
    numDel = this->maskTofHelper(*this->weightedEvents, tofMin, tofMax);
    break;
  case WEIGHTED_NOTIME:
    numOrig = this->weightedEventsNoTime->size();
    numDel = this->maskTofHelper(*this->weightedEventsNoTime, tofMin, tofMax);
    break;
  }
 
  if (numDel >= numOrig)
    this->clear(false);
}
 
// --------------------------------------------------------------------------
template <class T> std::size_t EventList::maskConditionHelper(std::vector<T> &events, const std::vector<bool> &mask) {
 
  // runs through the two synchronized vectors and delete elements
  // for condition false
  auto itm = std::find(mask.begin(), mask.end(), false);
  auto first = events.begin() + (itm - mask.begin());
 
  if (itm != mask.end()) {
    for (auto ite = first; ++ite != events.end() && ++itm != mask.end();) {
      if (*itm != false) {
        *first++ = std::move(*ite);
      }
    }
  }
 
  const auto n = static_cast<size_t>(events.end() - first);
  if (n != 0)
    events.erase(first, events.end());
 
  return n;
}
 
// --------------------------------------------------------------------------
void EventList::maskCondition(const std::vector<bool> &mask) {
 
  // mask size must match the number of events
  if (this->getNumberEvents() != mask.size())
    throw std::runtime_error("EventList::maskTof: tofMax must be > tofMin");
 
  // don't do anything with an emply list
  if (this->getNumberEvents() == 0)
    return;
 
  // Convert the list
  size_t numOrig = 0;
  size_t numDel = 0;
  switch (eventType) {
  case TOF:
    numOrig = this->events->size();
    numDel = this->maskConditionHelper(*this->events, mask);
    break;
  case WEIGHTED:
    numOrig = this->weightedEvents->size();
    numDel = this->maskConditionHelper(*this->weightedEvents, mask);
    break;
  case WEIGHTED_NOTIME:
    numOrig = this->weightedEventsNoTime->size();
    numDel = this->maskConditionHelper(*this->weightedEventsNoTime, mask);
    break;
  }
 
  if (numDel >= numOrig)
    this->clear(false);
}
 
// --------------------------------------------------------------------------
template <class T> void EventList::getTofsHelper(const std::vector<T> &events, std::vector<double> &tofs) {
  tofs.clear();
  for (auto itev = events.cbegin(); itev != events.cend(); ++itev)
    tofs.emplace_back(itev->m_tof);
}
 
void EventList::getTofs(std::vector<double> &tofs) const {
  // Set the capacity of the vector to avoid multiple resizes
  tofs.reserve(this->getNumberEvents());
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->getTofsHelper(*this->events, tofs);
    break;
  case WEIGHTED:
    this->getTofsHelper(*this->weightedEvents, tofs);
    break;
  case WEIGHTED_NOTIME:
    this->getTofsHelper(*this->weightedEventsNoTime, tofs);
    break;
  }
}
 
std::vector<double> EventList::getTofs() const {
  std::vector<double> tofs;
  this->getTofs(tofs);
  return tofs;
}
 
// --------------------------------------------------------------------------
template <class T> void EventList::getWeightsHelper(const std::vector<T> &events, std::vector<double> &weights) {
  weights.clear();
  weights.reserve(events.size());
  std::transform(events.cbegin(), events.cend(), std::back_inserter(weights),
                 [](const auto &event) { return event.weight(); });
}
 
void EventList::getWeights(std::vector<double> &weights) const {
  // Set the capacity of the vector to avoid multiple resizes
  weights.reserve(this->getNumberEvents());
 
  // Convert the list
  switch (eventType) {
  case WEIGHTED:
    this->getWeightsHelper(*this->weightedEvents, weights);
    break;
  case WEIGHTED_NOTIME:
    this->getWeightsHelper(*this->weightedEventsNoTime, weights);
    break;
  default:
    // not a weighted event type, return 1.0 for all.
    weights.assign(this->getNumberEvents(), 1.0);
    break;
  }
}
 
std::vector<double> EventList::getWeights() const {
  std::vector<double> weights;
  this->getWeights(weights);
  return weights;
}
 
// --------------------------------------------------------------------------
template <class T>
void EventList::getWeightErrorsHelper(const std::vector<T> &events, std::vector<double> &weightErrors) {
  weightErrors.clear();
  weightErrors.reserve(events.size());
  std::transform(events.cbegin(), events.cend(), std::back_inserter(weightErrors),
                 [](const auto &event) { return event.error(); });
}
 
void EventList::getWeightErrors(std::vector<double> &weightErrors) const {
  // Set the capacity of the vector to avoid multiple resizes
  weightErrors.reserve(this->getNumberEvents());
 
  // Convert the list
  switch (eventType) {
  case WEIGHTED:
    this->getWeightErrorsHelper(*this->weightedEvents, weightErrors);
    break;
  case WEIGHTED_NOTIME:
    this->getWeightErrorsHelper(*this->weightedEventsNoTime, weightErrors);
    break;
  default:
    // not a weighted event type, return 1.0 for all.
    weightErrors.assign(this->getNumberEvents(), 1.0);
    break;
  }
}
 
std::vector<double> EventList::getWeightErrors() const {
  std::vector<double> weightErrors;
  this->getWeightErrors(weightErrors);
  return weightErrors;
}
 
template <typename UnaryOperation>
std::vector<DateAndTime> EventList::eventTimesCalculator(const UnaryOperation &timesCalc) const {
  std::vector<DateAndTime> times;
  switch (eventType) {
  case TOF:
    times.reserve(events->size());
    std::transform(events->cbegin(), events->cend(), std::back_inserter(times), timesCalc);
    break;
  case WEIGHTED:
    times.reserve(weightedEvents->size());
    std::transform(weightedEvents->cbegin(), weightedEvents->cend(), std::back_inserter(times), timesCalc);
    break;
  case WEIGHTED_NOTIME:
    times.reserve(weightedEventsNoTime->size());
    std::transform(weightedEventsNoTime->cbegin(), weightedEventsNoTime->cend(), std::back_inserter(times), timesCalc);
    break;
  }
  return times;
}
 
std::vector<Mantid::Types::Core::DateAndTime> EventList::getPulseTimes() const {
  auto timeCalc = [](const auto &event) { return event.pulseTime(); };
  return eventTimesCalculator(timeCalc);
}
 
std::vector<DateAndTime> EventList::getPulseTOFTimes() const {
  auto timeCalc = [](const auto &event) { return event.pulseTOFTime(); };
  return eventTimesCalculator(timeCalc);
}
 
std::vector<DateAndTime> EventList::getPulseTOFTimesAtSample(const double &factor, const double &shift) const {
  auto timeCalc = [factor, shift](const auto &event) { return event.pulseTOFTimeAtSample(factor, shift); };
  return eventTimesCalculator(timeCalc);
}
 
// --------------------------------------------------------------------------
 
namespace { // anonymous namespace
template <class T> double getTofMinimumHelper(const std::vector<T> &events) {
  const auto result = std::min_element(events.cbegin(), events.cend(),
                                       [](const auto &left, const auto &right) { return left.tof() < right.tof(); });
  return result->tof();
}
 
template <class T> double getTofMaximumHelper(const std::vector<T> &events) {
  const auto result = std::max_element(events.cbegin(), events.cend(),
                                       [](const auto &left, const auto &right) { return left.tof() < right.tof(); });
  return result->tof();
}
} // anonymous namespace
 
double EventList::getTofMin() const {
  // set up as the maximum available double
  double tMin = std::numeric_limits<double>::max();
 
  // no events is a soft error
  if (this->empty())
    return tMin;
 
  // when events are ordered by tof just need the first value
  if (this->order == TOF_SORT) {
    switch (eventType) {
    case TOF:
      return this->events->front().tof();
    case WEIGHTED:
      return this->weightedEvents->front().tof();
    case WEIGHTED_NOTIME:
      return this->weightedEventsNoTime->front().tof();
    }
  }
 
  // now we are stuck with a linear search
  switch (eventType) {
  case TOF: {
    tMin = getTofMinimumHelper(*this->events);
    break;
  }
  case WEIGHTED: {
    tMin = getTofMinimumHelper(*this->weightedEvents);
    break;
  }
  case WEIGHTED_NOTIME: {
    tMin = getTofMinimumHelper(*this->weightedEventsNoTime);
    break;
  }
  }
 
  return tMin;
}
 
double EventList::getTofMax() const {
  // set up as the minimum available double
  double tMax = std::numeric_limits<double>::lowest();
 
  // no events is a soft error
  if (this->empty())
    return tMax;
 
  // when events are ordered by tof just need the first value
  if (this->order == TOF_SORT) {
    switch (eventType) {
    case TOF:
      return this->events->back().tof();
    case WEIGHTED:
      return this->weightedEvents->back().tof();
    case WEIGHTED_NOTIME:
      return this->weightedEventsNoTime->back().tof();
    }
  }
 
  // now we are stuck with a linear search
  switch (eventType) {
  case TOF: {
    tMax = getTofMaximumHelper(*this->events);
    break;
  }
  case WEIGHTED: {
    tMax = getTofMaximumHelper(*this->weightedEvents);
    break;
  }
  case WEIGHTED_NOTIME: {
    tMax = getTofMaximumHelper(*this->weightedEventsNoTime);
    break;
  }
  }
 
  return tMax;
}
 
// --------------------------------------------------------------------------
namespace { // anonymous namespace
template <class T> DateAndTime getPulseMinimumHelper(const std::vector<T> &events) {
  const auto result = std::min_element(events.cbegin(), events.cend(), [](const auto &left, const auto &right) {
    return left.pulseTime() < right.pulseTime();
  });
  return result->pulseTime();
}
 
template <class T> DateAndTime getPulseMaximumHelper(const std::vector<T> &events) {
  const auto result = std::max_element(events.cbegin(), events.cend(), [](const auto &left, const auto &right) {
    return left.pulseTime() < right.pulseTime();
  });
  return result->pulseTime();
}
} // anonymous namespace
 
DateAndTime EventList::getPulseTimeMin() const {
  // no events is a soft error
  if (this->empty())
    return DateAndTime::maximum();
 
  // when events are ordered by pulse time just need the first value
  if (this->order == PULSETIME_SORT) {
    switch (eventType) {
    case TOF:
      return this->events->front().pulseTime();
    case WEIGHTED:
      return this->weightedEvents->front().pulseTime();
    case WEIGHTED_NOTIME:
      return this->weightedEventsNoTime->front().pulseTime();
    }
  }
 
  // now we are stuck with a linear search
  switch (eventType) {
  case TOF:
    return getPulseMinimumHelper(*this->events);
  case WEIGHTED:
    return getPulseMinimumHelper(*this->weightedEvents);
  case WEIGHTED_NOTIME:
    return getPulseMinimumHelper(*this->weightedEventsNoTime);
  }
 
  return DateAndTime::maximum();
}
 
DateAndTime EventList::getPulseTimeMax() const {
  // no events is a soft error
  if (this->empty())
    return DateAndTime::minimum();
 
  // when events are ordered by pulse time just need the first value
  if (this->order == PULSETIME_SORT) {
    switch (eventType) {
    case TOF:
      return this->events->back().pulseTime();
    case WEIGHTED:
      return this->weightedEvents->back().pulseTime();
    case WEIGHTED_NOTIME:
      return this->weightedEventsNoTime->back().pulseTime();
    }
  }
 
  // now we are stuck with a linear search
  switch (eventType) {
  case TOF:
    return getPulseMaximumHelper(*this->events);
  case WEIGHTED:
    return getPulseMaximumHelper(*this->weightedEvents);
  case WEIGHTED_NOTIME:
    return getPulseMaximumHelper(*this->weightedEventsNoTime);
  }
 
  return DateAndTime::minimum();
}
 
void EventList::getPulseTimeMinMax(Mantid::Types::Core::DateAndTime &tMin,
                                   Mantid::Types::Core::DateAndTime &tMax) const {
  // set up as the minimum available date time.
  tMax = DateAndTime::minimum();
  tMin = DateAndTime::maximum();
 
  // no events is a soft error
  if (this->empty())
    return;
 
  // when events are ordered by pulse time just need the first/last values
  if (this->order == PULSETIME_SORT) {
    switch (eventType) {
    case TOF:
      tMin = this->events->front().pulseTime();
      tMax = this->events->back().pulseTime();
      return;
    case WEIGHTED:
      tMin = this->weightedEvents->front().pulseTime();
      tMax = this->weightedEvents->back().pulseTime();
      return;
    case WEIGHTED_NOTIME:
      tMin = this->weightedEventsNoTime->front().pulseTime();
      tMax = this->weightedEventsNoTime->back().pulseTime();
      return;
    }
  }
 
  // now we are stuck with a linear search
  // could this be done more efficiently than using ->at?
  size_t numEvents = this->getNumberEvents();
  DateAndTime temp = tMax; // start with the smallest possible value
  for (size_t i = 0; i < numEvents; i++) {
    switch (eventType) {
    case TOF:
      temp = this->events->at(i).pulseTime();
      break;
    case WEIGHTED:
      temp = this->weightedEvents->at(i).pulseTime();
      break;
    case WEIGHTED_NOTIME:
      temp = this->weightedEventsNoTime->at(i).pulseTime();
      break;
    }
    if (temp > tMax)
      tMax = temp;
    if (temp < tMin)
      tMin = temp;
  }
}
 
DateAndTime EventList::getTimeAtSampleMax(const double &tofFactor, const double &tofOffset) const {
  // set up as the minimum available date time.
  DateAndTime tMax = DateAndTime::minimum();
 
  // no events is a soft error
  if (this->empty())
    return tMax;
 
  // when events are ordered by time at sample just need the first value
  if (this->order == TIMEATSAMPLE_SORT) {
    switch (eventType) {
    case TOF:
      return calculateCorrectedFullTime(this->events->back(), tofFactor, tofOffset);
    case WEIGHTED:
      return calculateCorrectedFullTime(this->weightedEvents->back(), tofFactor, tofOffset);
    case WEIGHTED_NOTIME:
      return calculateCorrectedFullTime(this->weightedEventsNoTime->back(), tofFactor, tofOffset);
    }
  }
 
  // now we are stuck with a linear search
  size_t numEvents = this->getNumberEvents();
  DateAndTime temp = tMax; // start with the smallest possible value
  for (size_t i = 0; i < numEvents; i++) {
    switch (eventType) {
    case TOF:
      temp = calculateCorrectedFullTime(this->events->at(i), tofFactor, tofOffset);
      break;
    case WEIGHTED:
      temp = calculateCorrectedFullTime(this->weightedEvents->at(i), tofFactor, tofOffset);
      break;
    case WEIGHTED_NOTIME:
      temp = calculateCorrectedFullTime(this->weightedEventsNoTime->at(i), tofFactor, tofOffset);
      break;
    }
    if (temp > tMax)
      tMax = temp;
  }
  return tMax;
}
 
DateAndTime EventList::getTimeAtSampleMin(const double &tofFactor, const double &tofOffset) const {
  // set up as the minimum available date time.
  DateAndTime tMin = DateAndTime::maximum();
 
  // no events is a soft error
  if (this->empty())
    return tMin;
 
  // when events are ordered by time at sample just need the first value
  if (this->order == TIMEATSAMPLE_SORT) {
    switch (eventType) {
    case TOF:
      return calculateCorrectedFullTime(this->events->front(), tofFactor, tofOffset);
    case WEIGHTED:
      return calculateCorrectedFullTime(this->weightedEvents->front(), tofFactor, tofOffset);
    case WEIGHTED_NOTIME:
      return calculateCorrectedFullTime(this->weightedEventsNoTime->front(), tofFactor, tofOffset);
    }
  }
 
  // now we are stuck with a linear search
  size_t numEvents = this->getNumberEvents();
  DateAndTime temp = tMin; // start with the smallest possible value
  for (size_t i = 0; i < numEvents; i++) {
    switch (eventType) {
    case TOF:
      temp = calculateCorrectedFullTime(this->events->at(i), tofFactor, tofOffset);
      break;
    case WEIGHTED:
      temp = calculateCorrectedFullTime(this->weightedEvents->at(i), tofFactor, tofOffset);
      break;
    case WEIGHTED_NOTIME:
      temp = calculateCorrectedFullTime(this->weightedEventsNoTime->at(i), tofFactor, tofOffset);
      break;
    }
    if (temp < tMin)
      tMin = temp;
  }
  return tMin;
}
 
// --------------------------------------------------------------------------
template <class T> void EventList::setTofsHelper(std::vector<T> &events, const std::vector<double> &tofs) {
  if (tofs.empty())
    return;
 
  size_t x_size = tofs.size();
  if (events.size() != x_size)
    return; // should this throw an exception?
 
  for (size_t i = 0; i < x_size; ++i)
    events[i].m_tof = tofs[i];
}
 
// --------------------------------------------------------------------------
void EventList::setTofs(const MantidVec &tofs) {
  this->order = UNSORTED;
 
  // Convert the list
  switch (eventType) {
  case TOF:
    this->setTofsHelper(*this->events, tofs);
    break;
  case WEIGHTED:
    this->setTofsHelper(*this->weightedEvents, tofs);
    break;
  case WEIGHTED_NOTIME:
    this->setTofsHelper(*this->weightedEventsNoTime, tofs);
    break;
  }
}
 
// ==============================================================================================
// ----------- MULTIPLY AND DIVIDE ---------------------------------------
// ==============================================================================================
 
//------------------------------------------------------------------------------------------------
template <class T> void EventList::multiplyHelper(std::vector<T> &events, const double value, const double error) {
  // Square of the value
  const double valueSquared = value * value;
 
  auto itev_end = events.end();
 
  if (error == 0) {
    // Error-less calculation
    for (auto itev = events.begin(); itev != itev_end; itev++) {
      itev->m_errorSquared = static_cast<float>(itev->m_errorSquared * valueSquared);
      itev->m_weight *= static_cast<float>(value);
    }
  } else {
    // Carry the scalar error
    const double errorSquared = error * error; // Square of the value's error
    for (auto itev = events.begin(); itev != itev_end; itev++) {
      itev->m_errorSquared =
          static_cast<float>(itev->m_errorSquared * valueSquared + errorSquared * itev->m_weight * itev->m_weight);
      itev->m_weight *= static_cast<float>(value);
    }
  }
}
 
//------------------------------------------------------------------------------------------------
EventList &EventList::operator*=(const double value) {
  this->multiply(value);
  return *this;
}
 
//------------------------------------------------------------------------------------------------
void EventList::multiply(const double value, const double error) {
  // Do nothing if multiplying by exactly one and there is no error
  if ((value == 1.0) && (error == 0.0))
    return;
 
  switch (eventType) {
  case TOF:
    // Switch to weights if needed.
    this->switchTo(WEIGHTED);
    // Fall through
 
  case WEIGHTED:
    multiplyHelper(*this->weightedEvents, value, error);
    break;
 
  case WEIGHTED_NOTIME:
    multiplyHelper(*this->weightedEventsNoTime, value, error);
    break;
  }
}
 
//------------------------------------------------------------------------------------------------
template <class T>
void EventList::multiplyHistogramHelper(std::vector<T> &events, std::span<double const> X, std::span<double const> Y,
                                        std::span<double const> E) {
  // Validate inputs
  if ((X.size() < 2) || (Y.size() != E.size()) || (X.size() != 1 + Y.size())) {
    std::stringstream msg;
    msg << "EventList::multiply() was given invalid size or "
           "inconsistent histogram arrays: X["
        << X.size() << "] "
        << "Y[" << Y.size() << " E[" << E.size() << "]";
    throw std::invalid_argument(msg.str());
  }
 
  size_t x_size = X.size();
 
  // Iterate through all events (sorted by tof)
  auto itev = findFirstEvent(events, T(X[0]));
  auto itev_end = events.end();
  // The above can still take you to end() if no events above X[0], so check
  // again.
  if (itev == itev_end)
    return;
 
  // Find the first bin
  size_t bin = 0;
 
  // Multiplier values
  double value;
  double error;
  double valueSquared;
  double errorSquared;
 
  // If the tof is greater the first bin boundary, so we need to find the first
  // bin
  double tof = itev->tof();
  while (bin < x_size - 1) {
    // Within range?
    if ((tof >= X[bin]) && (tof < X[bin + 1]))
      break; // Stop increasing bin
    ++bin;
  }
 
  // New bin! Find what you are multiplying!
  value = Y[bin];
  error = E[bin];
  valueSquared = value * value;
  errorSquared = error * error;
 
  // Keep going through all the events
  while ((itev != itev_end) && (bin < x_size - 1)) {
    tof = itev->tof();
    while (bin < x_size - 1) {
      // Event is Within range?
      if ((tof >= X[bin]) && (tof < X[bin + 1])) {
        // Process this event. Multiply and calculate error.
        itev->m_errorSquared =
            static_cast<float>(itev->m_errorSquared * valueSquared + errorSquared * itev->m_weight * itev->m_weight);
        itev->m_weight *= static_cast<float>(value);
        break; // out of the bin-searching-while-loop
      }
      ++bin;
      if (bin >= x_size - 1)
        break;
 
      // New bin! Find what you are multiplying!
      value = Y[bin];
      error = E[bin];
      valueSquared = value * value;
      errorSquared = error * error;
    }
    ++itev;
  }
}
 
//------------------------------------------------------------------------------------------------
void EventList::multiply(std::span<double const> X, std::span<double const> Y, std::span<double const> E) {
  switch (eventType) {
  case TOF:
    // Switch to weights if needed.
    this->switchTo(WEIGHTED);
    // Fall through
 
  case WEIGHTED:
    // Sorting by tof is necessary for the algorithm
    this->sortTof();
    multiplyHistogramHelper(*this->weightedEvents, X, Y, E);
    break;
 
  case WEIGHTED_NOTIME:
    // Sorting by tof is necessary for the algorithm
    this->sortTof();
    multiplyHistogramHelper(*this->weightedEventsNoTime, X, Y, E);
    break;
  }
}
 
//------------------------------------------------------------------------------------------------
template <class T>
void EventList::divideHistogramHelper(std::vector<T> &events, std::span<double const> X, std::span<double const> Y,
                                      std::span<double const> E) {
  // Validate inputs
  if ((X.size() < 2) || (Y.size() != E.size()) || (X.size() != 1 + Y.size())) {
    std::stringstream msg;
    msg << "EventList::divide() was given invalid size or "
           "inconsistent histogram arrays: X["
        << X.size() << "] "
        << "Y[" << Y.size() << " E[" << E.size() << "]";
    throw std::invalid_argument(msg.str());
  }
 
  size_t x_size = X.size();
 
  // Iterate through all events (sorted by tof)
  auto itev = findFirstEvent(events, T(X[0]));
  auto itev_end = events.end();
  // The above can still take you to end() if no events above X[0], so check
  // again.
  if (itev == itev_end)
    return;
 
  // Find the first bin
  size_t bin = 0;
 
  // Multiplier values
  double value;
  double error;
  double valError_over_value_squared;
 
  // If the tof is greater the first bin boundary, so we need to find the first
  // bin
  double tof = itev->tof();
  while (bin < x_size - 1) {
    // Within range?
    if ((tof >= X[bin]) && (tof < X[bin + 1]))
      break; // Stop increasing bin
    ++bin;
  }
 
  // New bin! Find what you are multiplying!
  value = Y[bin];
  error = E[bin];
 
  // --- Division case ---
  if (value == 0) {
    value = std::numeric_limits<float>::quiet_NaN(); // Avoid divide by zero
    valError_over_value_squared = 0;
  } else
    valError_over_value_squared = error * error / (value * value);
 
  // Keep going through all the events
  while ((itev != events.end()) && (bin < x_size - 1)) {
    tof = itev->tof();
    while (bin < x_size - 1) {
      // Event is Within range?
      if ((tof >= X[bin]) && (tof < X[bin + 1])) {
        // Process this event. Divide and calculate error.
        double newWeight = itev->m_weight / value;
        itev->m_errorSquared = static_cast<float>(
            newWeight * newWeight *
            ((itev->m_errorSquared / (itev->m_weight * itev->m_weight)) + valError_over_value_squared));
        itev->m_weight = static_cast<float>(newWeight);
        break; // out of the bin-searching-while-loop
      }
      ++bin;
      if (bin >= x_size - 1)
        break;
 
      // New bin! Find what you are multiplying!
      value = Y[bin];
      error = E[bin];
 
      // --- Division case ---
      if (value == 0) {
        value = std::numeric_limits<float>::quiet_NaN(); // Avoid divide by zero
        valError_over_value_squared = 0;
      } else
        valError_over_value_squared = error * error / (value * value);
    }
    ++itev;
  }
}
 
//------------------------------------------------------------------------------------------------
void EventList::divide(std::span<double const> X, std::span<double const> Y, std::span<double const> E) {
  switch (eventType) {
  case TOF:
    // Switch to weights if needed.
    this->switchTo(WEIGHTED);
    // Fall through
 
  case WEIGHTED:
    // Sorting by tof is necessary for the algorithm
    this->sortTof();
    divideHistogramHelper(*this->weightedEvents, X, Y, E);
    break;
 
  case WEIGHTED_NOTIME:
    // Sorting by tof is necessary for the algorithm
    this->sortTof();
    divideHistogramHelper(*this->weightedEventsNoTime, X, Y, E);
    break;
  }
}
 
//------------------------------------------------------------------------------------------------
EventList &EventList::operator/=(const double value) {
  if (value == 0.0)
    throw std::invalid_argument("EventList::divide() called with value of 0.0. Cannot divide by zero.");
  this->multiply(1.0 / value, 0.0);
  return *this;
}
 
//------------------------------------------------------------------------------------------------
void EventList::divide(const double value, const double error) {
  if (value == 0.0)
    throw std::invalid_argument("EventList::divide() called with value of 0.0. Cannot divide by zero.");
  // Do nothing if dividing by exactly 1.0, no error
  else if (value == 1.0 && error == 0.0)
    return;
 
  // We'll multiply by 1/value
  double invValue = 1.0 / value;
  // Relative error remains the same
  double invError = (error / value) * invValue;
 
  this->multiply(invValue, invError);
}
 
// ==============================================================================================
// ----------- SPLITTING AND FILTERING ---------------------------------------
// ==============================================================================================
//------------------------------------------------------------------------------------------------
void EventList::filterByPulseTime(Types::Core::DateAndTime start, Types::Core::DateAndTime stop,
                                  EventList &output) const {
  if (this == &output) {
    throw std::invalid_argument("In-place filtering is not allowed");
  }
 
  // Start by sorting the event list by pulse time.
  this->sortPulseTime();
  // Clear the output
  output.clear();
  // Has to match the given type
  output.switchTo(eventType);
  output.setDetectorIDs(this->getDetectorIDs());
  output.setHistogram(m_histogram);
  output.setSortOrder(this->order);
 
  // Iterate through all events (sorted by pulse time)
  switch (eventType) {
  case TOF:
    filterByPulseTimeHelper(*this->events, start, stop, *output.events);
    break;
  case WEIGHTED:
    filterByPulseTimeHelper(*this->weightedEvents, start, stop, *output.weightedEvents);
    break;
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::filterByPulseTime() called on an "
                             "EventList that no longer has time information.");
    break;
  }
}
 
void EventList::filterByPulseTime(Kernel::TimeROI const *timeRoi, EventList *output) const {
 
  this->sortPulseTime();
  // Clear the output
 
  output->clear();
  output->setDetectorIDs(this->getDetectorIDs());
  output->setHistogram(m_histogram);
  // Has to match the given type
  output->switchTo(eventType);
 
  if ((timeRoi == nullptr) || (timeRoi->useAll())) {
    throw std::invalid_argument("TimeROI can not use all time");
  }
  const auto &intervals = timeRoi->toTimeIntervals();
  if (intervals.empty())
    return;
 
  switch (eventType) {
  case TOF:
    filterByTimeROIHelper(*this->events, intervals, output);
    break;
  case WEIGHTED:
    filterByTimeROIHelper(*this->weightedEvents, intervals, output);
    break;
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::filterByPulseTime() called on an "
                             "EventList that no longer has time information.");
    break;
  }
}
 
template <class T>
void EventList::filterByPulseTimeHelper(std::vector<T> &events, DateAndTime start, DateAndTime stop,
                                        std::vector<T> &output) {
  std::copy_if(events.begin(), events.end(), std::back_inserter(output),
               [start, stop](const T &t) { return (t.m_pulsetime >= start) && (t.m_pulsetime < stop); });
}
 
template <class T>
void EventList::filterByTimeROIHelper(std::vector<T> &events, const std::vector<Kernel::TimeInterval> &intervals,
                                      EventList *output) {
  // Iterate through the splitter at the same time
  auto itspl = intervals.cbegin();
  auto itspl_end = intervals.cend();
  // Iterate through all events (sorted by tof)
  auto itev = events.cbegin();
  auto itev_end = events.cend();
 
  // This is the time of the first section. Anything before is thrown out.
  while (itspl != itspl_end) {
    // Get the splitting interval times and destination
    DateAndTime start = itspl->start();
    DateAndTime stop = itspl->stop();
    // Skip the events before the start of the time
    while ((itev != itev_end) && (itev->m_pulsetime < start))
      itev++;
 
    // Go through all the events that are in the interval (if any)
    while ((itev != itev_end) && (itev->m_pulsetime < stop)) {
      // Copy the event into another
      const T eventCopy(*itev);
      output->addEventQuickly(eventCopy);
      ++itev;
    }
 
    // Go to the next interval
    ++itspl;
    // But if we reached the end, then we are done.
    if (itspl == itspl_end)
      break;
 
    // No need to keep looping through the filter if we are out of events
    if (itev == itev_end)
      break;
  }
  // Done!
}
 
void EventList::filterInPlace(Kernel::TimeROI const *timeRoi) {
  if (timeRoi == nullptr) {
    throw std::runtime_error("TimeROI can not be a nullptr\n");
  }
  if (timeRoi->useAll()) {
    throw std::invalid_argument("TimeROI can not be empty\n");
  }
  // Start by sorting the event list by pulse time.
  this->sortPulseTime();
 
  // Iterate through all events (sorted by pulse time)
  switch (eventType) {
  case TOF:
    filterInPlaceHelper(timeRoi, *this->events);
    break;
  case WEIGHTED:
    filterInPlaceHelper(timeRoi, *this->weightedEvents);
    break;
  case WEIGHTED_NOTIME:
    throw std::runtime_error("EventList::filterInPlace() called on an "
                             "EventList that no longer has time information.");
    break;
  }
}
 
template <class T>
void EventList::filterInPlaceHelper(Kernel::TimeROI const *timeRoi, typename std::vector<T> &events) {
 
  const auto splitter = timeRoi->toTimeIntervals();
  // Iterate through the splitter at the same time
  auto itspl = splitter.cbegin();
  auto itspl_end = splitter.cend();
  DateAndTime start, stop;
 
  // Iterate for the input
  auto itev = events.begin();
  auto itev_end = events.end();
 
  // Iterator for the outputted list; will follow the input except when events
  // are dropped.
  auto itOut = events.begin();
 
  // This is the time of the first section. Anything before is thrown out.
  while (itspl != itspl_end) {
    // Get the splitting interval times and destination
    start = itspl->start();
    stop = itspl->stop();
    // Skip the events before the start of the time
    while ((itev != itev_end) && (itev->m_pulsetime < start))
      itev++;
 
    // Are we aligned in the input vs output?
    bool copyingInPlace = (itOut == itev);
    if (copyingInPlace) {
      while ((itev != itev_end) && (itev->m_pulsetime < stop))
        ++itev;
      // Make sure the iterators still match
      itOut = itev;
    } else {
      // Go through all the events that are in the interval (if any)
      while ((itev != itev_end) && (itev->m_pulsetime < stop)) {
        *itOut = *itev;
        ++itOut;
        ++itev;
      }
    }
 
    // Go to the next interval
    ++itspl;
    // But if we reached the end, then we are done.
    if (itspl == itspl_end)
      break;
 
    // No need to keep looping through the filter if we are out of events
    if (itev == itev_end)
      break;
 
  } // Looping through entries in the splitter vector
 
  // Ok, now resize the event list to reflect the fact that it (probably) shrank
  events.resize(std::size_t(std::distance(events.begin(), itOut)));
}
 
void EventList::initializePartials(std::map<int, EventList *> partials) const {
 
  // collect the state from events which is to be transferred to the partials
  bool removeDetIDs{true};
  const auto histogramLocal = this->getHistogram();
  const auto eventTypeLocal = this->getEventType();
 
  // lambda expression initializing one partial
  auto initPartial = [&](EventList *partial) {
    partial->clear(removeDetIDs);
    partial->copyInfoFrom(*this);
    partial->setHistogram(histogramLocal);
    partial->switchTo(eventTypeLocal);
  };
 
  // iterate over the partials
  std::for_each(partials.cbegin(), partials.cend(),
                [&](const std::pair<int, EventList *> &pair) { initPartial(pair.second); });
}
 
void getEventsFrom(EventList &el, std::vector<TofEvent> *&events) { events = &el.getEvents(); }
void getEventsFrom(const EventList &el, std::vector<TofEvent> const *&events) { events = &el.getEvents(); }
 
void getEventsFrom(EventList &el, std::vector<WeightedEvent> *&events) { events = &el.getWeightedEvents(); }
void getEventsFrom(const EventList &el, std::vector<WeightedEvent> const *&events) { events = &el.getWeightedEvents(); }
 
void getEventsFrom(EventList &el, std::vector<WeightedEventNoTime> *&events) { events = &el.getWeightedEventsNoTime(); }
void getEventsFrom(const EventList &el, std::vector<WeightedEventNoTime> const *&events) {
  events = &el.getWeightedEventsNoTime();
}
 
template <class T>
void EventList::convertUnitsViaTofHelper(typename std::vector<T> &events, Mantid::Kernel::Unit const *fromUnit,
                                         Mantid::Kernel::Unit const *toUnit) {
  for (auto &itev : events) {
    // Conver to TOF
    const double tof = fromUnit->singleToTOF(itev.m_tof);
    // And back from TOF to whatever
    itev.m_tof = toUnit->singleFromTOF(tof);
  }
}
 
//--------------------------------------------------------------------------
void EventList::convertUnitsViaTof(Mantid::Kernel::Unit const *fromUnit, Mantid::Kernel::Unit const *toUnit) {
  // Check for initialized
  if (!fromUnit || !toUnit)
    throw std::runtime_error("EventList::convertUnitsViaTof(): one of the units is NULL!");
  if (!fromUnit->isInitialized())
    throw std::runtime_error("EventList::convertUnitsViaTof(): fromUnit is not initialized!");
  if (!toUnit->isInitialized())
    throw std::runtime_error("EventList::convertUnitsViaTof(): toUnit is not initialized!");
 
  switch (eventType) {
  case TOF:
    convertUnitsViaTofHelper(*this->events, fromUnit, toUnit);
    break;
  case WEIGHTED:
    convertUnitsViaTofHelper(*this->weightedEvents, fromUnit, toUnit);
    break;
  case WEIGHTED_NOTIME:
    convertUnitsViaTofHelper(*this->weightedEventsNoTime, fromUnit, toUnit);
    break;
  }
}
 
//--------------------------------------------------------------------------
template <class T>
void EventList::convertUnitsQuicklyHelper(typename std::vector<T> &events, const double &factor, const double &power) {
  for (auto &event : events) {
    // Output unit = factor * (input) ^ power
    event.m_tof = factor * std::pow(event.m_tof, power);
  }
}
 
//--------------------------------------------------------------------------
void EventList::convertUnitsQuickly(const double &factor, const double &power) {
  switch (eventType) {
  case TOF:
    convertUnitsQuicklyHelper(*this->events, factor, power);
    break;
  case WEIGHTED:
    convertUnitsQuicklyHelper(*this->weightedEvents, factor, power);
    break;
  case WEIGHTED_NOTIME:
    convertUnitsQuicklyHelper(*this->weightedEventsNoTime, factor, power);
    break;
  }
}
 
HistogramData::Histogram &EventList::mutableHistogramRef() {
  if (mru)
    mru->deleteIndex(this);
  return m_histogram;
}
 
void EventList::checkAndSanitizeHistogram(HistogramData::Histogram &histogram) {
  if (histogram.xMode() != HistogramData::Histogram::XMode::BinEdges)
    throw std::runtime_error("EventList: setting histogram with storage mode "
                             "other than BinEdges is not possible");
  if (histogram.sharedY() || histogram.sharedE())
    throw std::runtime_error("EventList: setting histogram data with non-null "
                             "Y or E data is not possible");
  // Avoid flushing of YMode: we only change X but YMode depends on events.
  if (histogram.yMode() == HistogramData::Histogram::YMode::Uninitialized)
    histogram.setYMode(m_histogram.yMode());
  if (histogram.yMode() != m_histogram.yMode())
    throw std::runtime_error("EventList: setting histogram data with different "
                             "YMode is not possible");
}
 
void EventList::checkWorksWithPoints() const {
  throw std::runtime_error("EventList: setting Points as X data is not "
                           "possible, only BinEdges are supported");
}
 
void EventList::checkIsYAndEWritable() const {
  throw std::runtime_error("EventList: Cannot set Y or E data, these data are "
                           "generated automatically based on the events");
}
 
} // namespace Mantid::DataObjects