EQSANSTofStructure.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 "MantidAlgorithms/EQSANSTofStructure.h"
#include "MantidAPI/Run.h"
#include "MantidAPI/SpectrumInfo.h"
#include "MantidAPI/WorkspaceUnitValidator.h"
#include "MantidDataObjects/EventList.h"
#include "MantidDataObjects/EventWorkspace.h"
#include "MantidDataObjects/Events.h"
#include "MantidGeometry/Instrument.h"
#include "MantidKernel/TimeSeriesProperty.h"
 
#include <vector>
 
namespace Mantid::Algorithms {
 
// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(EQSANSTofStructure)
 
using namespace Kernel;
using namespace API;
using namespace DataObjects;
using namespace Geometry;
using Types::Event::TofEvent;
 
EQSANSTofStructure::EQSANSTofStructure()
    : API::Algorithm(), frame_tof0(0.), flight_path_correction(false), low_tof_cut(0.), high_tof_cut(0.) {}
 
void EQSANSTofStructure::init() {
  declareProperty(std::make_unique<WorkspaceProperty<EventWorkspace>>("InputWorkspace", "", Direction::Input,
                                                                      std::make_shared<WorkspaceUnitValidator>("TOF")),
                  "Workspace to apply the TOF correction to");
  declareProperty("FlightPathCorrection", false, "If True, the neutron flight path correction will be applied",
                  Kernel::Direction::Input);
  declareProperty("LowTOFCut", 0.0,
                  "Width of the TOF margin to cut on the "
                  "lower end of the TOF distribution of each "
                  "frame",
                  Kernel::Direction::Input);
  declareProperty("HighTOFCut", 0.0,
                  "Width of the TOF margin to cut on the "
                  "upper end of the TOF distribution of "
                  "each frame",
                  Kernel::Direction::Input);
 
  // Output parameters
  declareProperty("FrameSkipping", false, "If True, the data was taken in frame skipping mode",
                  Kernel::Direction::Output);
  declareProperty("TofOffset", 0.0, "TOF offset that was applied to the data", Kernel::Direction::Output);
  declareProperty("WavelengthMin", 0.0, "Lower bound of the wavelength distribution of the first frame",
                  Kernel::Direction::Output);
  declareProperty("WavelengthMax", 0.0, "Upper bound of the wavelength distribution of the first frame",
                  Kernel::Direction::Output);
  declareProperty("WavelengthMinFrame2", 0.0, "Lower bound of the wavelength distribution of the second frame",
                  Kernel::Direction::Output);
  declareProperty("WavelengthMaxFrame2", 0.0, "Upper bound of the wavelength distribution of the second frame",
                  Kernel::Direction::Output);
}
 
void EQSANSTofStructure::exec() {
  EventWorkspace_sptr inputWS = getProperty("InputWorkspace");
  flight_path_correction = getProperty("FlightPathCorrection");
  low_tof_cut = getProperty("LowTOFCut");
  high_tof_cut = getProperty("HighTOFCut");
 
  // Calculate the frame width
  auto frequencyLog = dynamic_cast<TimeSeriesProperty<double> *>(inputWS->run().getLogData("frequency"));
  if (!frequencyLog) {
    throw std::runtime_error("Frequency log not found.");
  }
  double frequency = frequencyLog->getStatistics().mean;
  double tof_frame_width = 1.0e6 / frequency;
 
  // Determine whether we need frame skipping or not by checking the chopper
  // speed
  bool frame_skipping = false;
  auto chopper_speedLog = dynamic_cast<TimeSeriesProperty<double> *>(inputWS->run().getLogData("Speed1"));
  if (!chopper_speedLog) {
    throw std::runtime_error("Chopper speed log not found.");
  }
  const double chopper_speed = chopper_speedLog->getStatistics().mean;
  if (std::fabs(chopper_speed - frequency / 2.0) < 1.0)
    frame_skipping = true;
 
  // Get TOF offset
  frame_tof0 = getTofOffset(inputWS, frame_skipping);
 
  // Calculate the frame width
  double tmp_frame_width = frame_skipping ? tof_frame_width * 2.0 : tof_frame_width;
  double frame_offset = 0.0;
  if (frame_tof0 >= tmp_frame_width)
    frame_offset = tmp_frame_width * (static_cast<int>(frame_tof0 / tmp_frame_width));
 
  this->execEvent(inputWS, frame_tof0, frame_offset, tof_frame_width, tmp_frame_width, frame_skipping);
}
 
void EQSANSTofStructure::execEvent(const Mantid::DataObjects::EventWorkspace_sptr &inputWS, double threshold,
                                   double frame_offset, double tof_frame_width, double tmp_frame_width,
                                   bool frame_skipping) {
  const size_t numHists = inputWS->getNumberHistograms();
  Progress progress(this, 0.0, 1.0, numHists);
 
  // This now points to the correct distance and makes the naming clearer
  // Get the nominal sample flange-to-detector distance (in mm)
  Mantid::Kernel::Property *prop = inputWS->run().getProperty("sampleflange_detector_distance");
  auto dp = dynamic_cast<Mantid::Kernel::PropertyWithValue<double> *>(prop);
  if (!dp) {
    throw std::runtime_error("sampleflange_detector_distance log not found.");
  }
  const double SFDD = *dp / 1000.0;
 
  const auto &spectrumInfo = inputWS->spectrumInfo();
  const auto l1 = spectrumInfo.l1();
 
  // Loop through the spectra and apply correction
  PARALLEL_FOR_IF(Kernel::threadSafe(*inputWS))
  for (int64_t ispec = 0; ispec < int64_t(numHists); ++ispec) {
    PARALLEL_START_INTERRUPT_REGION
 
    if (!spectrumInfo.hasDetectors(ispec)) {
      g_log.warning() << "Workspace index " << ispec << " has no detector assigned to it - discarding\n";
      continue;
    }
    const auto l2 = spectrumInfo.l2(ispec);
    double tof_factor = (l1 + l2) / (l1 + SFDD);
 
    // Get the pointer to the output event list
    std::vector<TofEvent> &events = inputWS->getSpectrum(ispec).getEvents();
    std::vector<TofEvent>::iterator it;
    std::vector<TofEvent> clean_events;
 
    for (it = events.begin(); it < events.end(); ++it) {
      double newtof = it->tof();
      newtof += frame_offset;
      // Correct for the scattered neutron flight path
      if (flight_path_correction)
        newtof /= tof_factor;
 
      while (newtof < threshold)
        newtof += tmp_frame_width;
 
      // Remove events that don't fall within the accepted time window
      double rel_tof = newtof - frame_tof0;
      double x = (static_cast<int>(floor(rel_tof * 10)) % static_cast<int>(floor(tof_frame_width * 10))) * 0.1;
      if (x < low_tof_cut || x > tof_frame_width - high_tof_cut) {
        continue;
      }
      // At this point the events in the second frame are still off by a frame
      if (frame_skipping && rel_tof > tof_frame_width)
        newtof += tof_frame_width;
      clean_events.emplace_back(newtof, it->pulseTime());
    }
    events.clear();
    events.reserve(clean_events.size());
    for (it = clean_events.begin(); it < clean_events.end(); ++it) {
      events.emplace_back(*it);
    }
 
    progress.report("TOF structure");
    PARALLEL_END_INTERRUPT_REGION
  }
  PARALLEL_CHECK_INTERRUPT_REGION
}
 
double EQSANSTofStructure::getTofOffset(const EventWorkspace_const_sptr &inputWS, bool frame_skipping) {
  //# Storage for chopper information read from the logs
  double chopper_set_phase[4] = {0, 0, 0, 0};
  double chopper_speed[4] = {0, 0, 0, 0};
  double chopper_actual_phase[4] = {0, 0, 0, 0};
  double chopper_wl_1[4] = {0, 0, 0, 0};
  double chopper_wl_2[4] = {0, 0, 0, 0};
  double frame_wl_1 = 0;
  double frame_srcpulse_wl_1 = 0;
  double frame_wl_2 = 0;
  double chopper_srcpulse_wl_1[4] = {0, 0, 0, 0};
  double chopper_frameskip_wl_1[4] = {0, 0, 0, 0};
  double chopper_frameskip_wl_2[4] = {0, 0, 0, 0};
  double chopper_frameskip_srcpulse_wl_1[4] = {0, 0, 0, 0};
 
  // Calculate the frame width
  auto frequencyLog = dynamic_cast<TimeSeriesProperty<double> *>(inputWS->run().getLogData("frequency"));
  if (!frequencyLog) {
    throw std::runtime_error("Frequency log not found.");
  }
  double frequency = frequencyLog->getStatistics().mean;
  double tof_frame_width = 1.0e6 / frequency;
 
  double tmp_frame_width = tof_frame_width;
  if (frame_skipping)
    tmp_frame_width *= 2.0;
 
  // Choice of parameter set
  int m_set = 0;
  if (frame_skipping)
    m_set = 1;
 
  bool first = true;
  bool first_skip = true;
  double frameskip_wl_1 = 0;
  double frameskip_srcpulse_wl_1 = 0;
  double frameskip_wl_2 = 0;
 
  for (int i = 0; i < 4; i++) {
    // Read chopper information
    std::ostringstream phase_str;
    phase_str << "Phase" << i + 1;
    auto log = dynamic_cast<TimeSeriesProperty<double> *>(inputWS->run().getLogData(phase_str.str()));
    if (!log) {
      throw std::runtime_error("Phase log not found.");
    }
    chopper_set_phase[i] = log->getStatistics().mean;
    std::ostringstream speed_str;
    speed_str << "Speed" << i + 1;
    log = dynamic_cast<TimeSeriesProperty<double> *>(inputWS->run().getLogData(speed_str.str()));
    if (!log) {
      throw std::runtime_error("Speed log not found.");
    }
    chopper_speed[i] = log->getStatistics().mean;
 
    // Only process choppers with non-zero speed
    if (chopper_speed[i] <= 0)
      continue;
 
    chopper_actual_phase[i] = chopper_set_phase[i] - CHOPPER_PHASE_OFFSET[m_set][i];
 
    while (chopper_actual_phase[i] < 0)
      chopper_actual_phase[i] += tmp_frame_width;
 
    double x1 = (chopper_actual_phase[i] - (tmp_frame_width * 0.5 * CHOPPER_ANGLE[i] / 360.)); // opening edge
    double x2 = (chopper_actual_phase[i] + (tmp_frame_width * 0.5 * CHOPPER_ANGLE[i] / 360.)); // closing edge
    if (!frame_skipping)                                                                       // not skipping
    {
      while (x1 < 0) {
        x1 += tmp_frame_width;
        x2 += tmp_frame_width;
      }
    }
 
    if (x1 > 0) {
      chopper_wl_1[i] = 3.9560346 * x1 / CHOPPER_LOCATION[i];
      chopper_srcpulse_wl_1[i] = 3.9560346 * (x1 - chopper_wl_1[i] * PULSEWIDTH) / CHOPPER_LOCATION[i];
    } else
      chopper_wl_1[i] = chopper_srcpulse_wl_1[i] = 0.;
 
    if (x2 > 0)
      chopper_wl_2[i] = 3.9560346 * x2 / CHOPPER_LOCATION[i];
    else
      chopper_wl_2[i] = 0.;
 
    if (first) {
      frame_wl_1 = chopper_wl_1[i];
      frame_srcpulse_wl_1 = chopper_srcpulse_wl_1[i];
      frame_wl_2 = chopper_wl_2[i];
      first = false;
    } else {
      if (frame_skipping && i == 2) // ignore chopper 1 and 2 forthe shortest wl.
      {
        frame_wl_1 = chopper_wl_1[i];
        frame_srcpulse_wl_1 = chopper_srcpulse_wl_1[i];
      }
      if (frame_wl_1 < chopper_wl_1[i])
        frame_wl_1 = chopper_wl_1[i];
      if (frame_wl_2 > chopper_wl_2[i])
        frame_wl_2 = chopper_wl_2[i];
      if (frame_srcpulse_wl_1 < chopper_srcpulse_wl_1[i])
        frame_srcpulse_wl_1 = chopper_srcpulse_wl_1[i];
    }
 
    if (frame_skipping) {
      if (x1 > 0) {
        x1 += tof_frame_width; // skipped pulse
        chopper_frameskip_wl_1[i] = 3.9560346 * x1 / CHOPPER_LOCATION[i];
        chopper_frameskip_srcpulse_wl_1[i] = 3.9560346 * (x1 - chopper_wl_1[i] * PULSEWIDTH) / CHOPPER_LOCATION[i];
      } else
        chopper_wl_1[i] = chopper_srcpulse_wl_1[i] = 0.;
 
      if (x2 > 0) {
        x2 += tof_frame_width;
        chopper_frameskip_wl_2[i] = 3.9560346 * x2 / CHOPPER_LOCATION[i];
      } else
        chopper_wl_2[i] = 0.;
 
      if (i < 2 && chopper_frameskip_wl_1[i] > chopper_frameskip_wl_2[i])
        continue;
 
      if (first_skip) {
        frameskip_wl_1 = chopper_frameskip_wl_1[i];
        frameskip_srcpulse_wl_1 = chopper_frameskip_srcpulse_wl_1[i];
        frameskip_wl_2 = chopper_frameskip_wl_2[i];
        first_skip = false;
      } else {
        if (i == 2) // ignore chopper 1 and 2 forthe longest wl.
          frameskip_wl_2 = chopper_frameskip_wl_2[i];
 
        if (chopper_frameskip_wl_1[i] < chopper_frameskip_wl_2[i] && frameskip_wl_1 < chopper_frameskip_wl_1[i])
          frameskip_wl_1 = chopper_frameskip_wl_1[i];
 
        if (chopper_frameskip_wl_1[i] < chopper_frameskip_wl_2[i] &&
            frameskip_srcpulse_wl_1 < chopper_frameskip_srcpulse_wl_1[i])
          frameskip_srcpulse_wl_1 = chopper_frameskip_srcpulse_wl_1[i];
 
        if (frameskip_wl_2 > chopper_frameskip_wl_2[i])
          frameskip_wl_2 = chopper_frameskip_wl_2[i];
      }
    }
  }
 
  if (frame_wl_1 >= frame_wl_2) // too many frames later. So figure it out
  {
    double n_frame[4] = {0, 0, 0, 0};
    double c_wl_1[4] = {0, 0, 0, 0};
    double c_wl_2[4] = {0, 0, 0, 0};
    bool passed = false;
 
    do {
      frame_wl_1 = c_wl_1[0] = chopper_wl_1[0] + 3.9560346 * n_frame[0] * tof_frame_width / CHOPPER_LOCATION[0];
      frame_wl_2 = c_wl_2[0] = chopper_wl_2[0] + 3.9560346 * n_frame[0] * tof_frame_width / CHOPPER_LOCATION[0];
 
      for (int i = 1; i < 4; i++) {
        n_frame[i] = n_frame[i - 1] - 1;
        passed = false;
 
        do {
          n_frame[i] += 1;
          c_wl_1[i] = chopper_wl_1[i] + 3.9560346 * n_frame[i] * tof_frame_width / CHOPPER_LOCATION[i];
          c_wl_2[i] = chopper_wl_2[i] + 3.9560346 * n_frame[i] * tof_frame_width / CHOPPER_LOCATION[i];
 
          if (frame_wl_1 < c_wl_2[i] && frame_wl_2 > c_wl_1[i]) {
            passed = true;
            break;
          }
          if (frame_wl_2 < c_wl_1[i])
            break; // over shot
        } while (n_frame[i] - n_frame[i - 1] < 10);
 
        if (!passed) {
          n_frame[0] += 1;
          break;
        } else {
          if (frame_wl_1 < c_wl_1[i])
            frame_wl_1 = c_wl_1[i];
          if (frame_wl_2 > c_wl_2[i])
            frame_wl_2 = c_wl_2[i];
        }
      }
    } while (!passed && n_frame[0] < 99);
 
    if (frame_wl_2 > frame_wl_1) {
      int n = 3;
      if (c_wl_1[2] > c_wl_1[3])
        n = 2;
 
      frame_srcpulse_wl_1 = c_wl_1[n] - 3.9560346 * c_wl_1[n] * PULSEWIDTH / CHOPPER_LOCATION[n];
 
      for (int i = 0; i < 4; i++) {
        chopper_wl_1[i] = c_wl_1[i];
        chopper_wl_2[i] = c_wl_2[i];
        if (frame_skipping) {
          chopper_frameskip_wl_1[i] = c_wl_1[i] + 3.9560346 * 2. * tof_frame_width / CHOPPER_LOCATION[i];
          chopper_frameskip_wl_2[i] = c_wl_2[i] + 3.9560346 * 2. * tof_frame_width / CHOPPER_LOCATION[i];
          if (i == 0) {
            frameskip_wl_1 = chopper_frameskip_wl_1[i];
            frameskip_wl_2 = chopper_frameskip_wl_2[i];
          } else {
            if (frameskip_wl_1 < chopper_frameskip_wl_1[i])
              frameskip_wl_1 = chopper_frameskip_wl_1[i];
            if (frameskip_wl_2 > chopper_frameskip_wl_2[i])
              frameskip_wl_2 = chopper_frameskip_wl_2[i];
          }
        }
      }
    } else
      frame_srcpulse_wl_1 = 0.0;
  }
  // Get source and detector locations
  // get the name of the mapping file as set in the parameter files
  std::vector<std::string> temp = inputWS->getInstrument()->getStringParameter("detector-name");
  std::string det_name = "detector1";
  if (temp.empty())
    g_log.information() << "The instrument parameter file does not contain the "
                           "'detector-name' parameter: trying 'detector1'";
  else
    det_name = temp[0];
 
  // Checked 8/11/2017 here detector_z is sfdd which has been updated
  // in eqsansload.cpp
  double source_z = inputWS->getInstrument()->getSource()->getPos().Z();
  double detector_z = inputWS->getInstrument()->getComponentByName(det_name)->getPos().Z();
 
  double source_to_detector = (detector_z - source_z) * 1000.0;
  frame_tof0 = frame_srcpulse_wl_1 / 3.9560346 * source_to_detector;
 
  g_log.information() << "Frame width " << tmp_frame_width << '\n';
  g_log.information() << "TOF offset = " << frame_tof0 << " microseconds\n";
  g_log.information() << "Band defined by T1-T4 " << frame_wl_1 << " " << frame_wl_2;
  if (frame_skipping)
    g_log.information() << " + " << frameskip_wl_1 << " " << frameskip_wl_2 << '\n';
  else
    g_log.information() << '\n';
  g_log.information() << "Chopper    Actual Phase    Lambda1    Lambda2\n";
  for (int i = 0; i < 4; i++)
    g_log.information() << i << "    " << chopper_actual_phase[i] << "  " << chopper_wl_1[i] << "  " << chopper_wl_2[i]
                        << '\n';
 
  // Checked 8/10/2017
  double low_wl_discard = 3.9560346 * low_tof_cut / source_to_detector;
  double high_wl_discard = 3.9560346 * high_tof_cut / source_to_detector;
 
  setProperty("FrameSkipping", frame_skipping);
  setProperty("TofOffset", frame_tof0);
  setProperty("WavelengthMin", frame_wl_1 + low_wl_discard);
  setProperty("WavelengthMax", frame_wl_2 - high_wl_discard);
  if (frame_skipping) {
    setProperty("WavelengthMinFrame2", frameskip_wl_1 + low_wl_discard);
    setProperty("WavelengthMaxFrame2", frameskip_wl_2 - high_wl_discard);
  }
 
  return frame_tof0;
}
 
} // namespace Mantid::Algorithms