ConvertSpectrumAxis2.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/ConvertSpectrumAxis2.h"
#include "MantidAPI/InstrumentValidator.h"
#include "MantidAPI/NumericAxis.h"
#include "MantidAPI/Run.h"
#include "MantidAPI/SpectraAxisValidator.h"
#include "MantidAPI/SpectrumInfo.h"
#include "MantidDataObjects/EventWorkspace.h"
#include "MantidDataObjects/WorkspaceCreation.h"
#include "MantidGeometry/Instrument.h"
#include "MantidGeometry/Instrument/ComponentInfo.h"
#include "MantidGeometry/Instrument/ReferenceFrame.h"
#include "MantidHistogramData/Histogram.h"
#include "MantidHistogramData/HistogramBuilder.h"
#include "MantidKernel/BoundedValidator.h"
#include "MantidKernel/CompositeValidator.h"
#include "MantidKernel/ListValidator.h"
#include "MantidKernel/Unit.h"
#include "MantidKernel/UnitConversion.h"
#include "MantidKernel/UnitFactory.h"
#include "MantidTypes/SpectrumDefinition.h"
 
#include <cfloat>
 
constexpr double rad2deg = 180.0 / M_PI;
 
namespace Mantid::Algorithms {
// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(ConvertSpectrumAxis2)
using namespace Kernel;
using namespace API;
using namespace Geometry;
using namespace DataObjects;
using namespace HistogramData;
 
void ConvertSpectrumAxis2::init() {
  // Validator for Input Workspace
  auto wsVal = std::make_shared<CompositeValidator>();
  wsVal->add<SpectraAxisValidator>();
  wsVal->add<InstrumentValidator>();
  declareProperty(std::make_unique<WorkspaceProperty<>>("InputWorkspace", "", Direction::Input, wsVal),
                  "The name of the input workspace.");
  declareProperty(std::make_unique<WorkspaceProperty<>>("OutputWorkspace", "", Direction::Output),
                  "The name to use for the output workspace.");
  std::vector<std::string> targetOptions{
      "Theta",           "SignedTheta", "InPlaneTwoTheta", "SignedInPlaneTwoTheta", "ElasticQ",
      "ElasticQSquared", "theta",       "signed_theta",    "ElasticDSpacing"};
  declareProperty("Target", "", std::make_shared<StringListValidator>(targetOptions),
                  "The unit to which spectrum axis is converted to - \"theta\" (for the "
                  "angle in degrees), Q or Q^2, where elastic Q is evaluated at EFixed. "
                  "InPlaneTwoTheta and SignedInPlaneTwoTheta are the angle when each point "
                  "is projected on the horizontal plane."
                  "Note that 'theta' and 'signed_theta' are there for compatibility "
                  "purposes; they are the same as 'Theta' and 'SignedTheta' respectively");
  std::vector<std::string> eModeOptions;
  eModeOptions.emplace_back("Direct");
  eModeOptions.emplace_back("Indirect");
  declareProperty("EMode", "Direct", std::make_shared<StringListValidator>(eModeOptions),
                  "Some unit conversions require this value to be set "
                  "(\"Direct\" or \"Indirect\")");
  auto mustBePositive = std::make_shared<BoundedValidator<double>>();
  mustBePositive->setLower(0.0);
  declareProperty("EFixed", EMPTY_DBL(), mustBePositive,
                  "Value of fixed energy in meV : EI (EMode=Direct) or EF "
                  "(EMode=Indirect))");
 
  declareProperty("OrderAxis", true,
                  "Whether or not to sort the resulting"
                  " spectrum axis.");
}
 
void ConvertSpectrumAxis2::exec() {
  // Get the input workspace.
  API::MatrixWorkspace_sptr inputWS = getProperty("InputWorkspace");
  // Assign value to the member variable storing the number of histograms.
  const size_t nHist = inputWS->getNumberHistograms();
 
  // The unit to convert to.
  const std::string unitTarget = getProperty("Target");
 
  // Whether needs to be ordered
  m_toOrder = getProperty("OrderAxis");
  size_t nProgress = nHist;
  if (m_toOrder) {
    // we will need to loop twice, once to build the indexMap,
    // once to copy over the spectra and set the output
    nProgress *= 2;
  } else {
    m_axis.reserve(nHist);
  }
 
  Progress progress(this, 0.0, 1.0, nProgress);
  // Call the functions to convert to the different forms of theta or Q.
  if (unitTarget == "theta" || unitTarget == "Theta" || unitTarget == "signed_theta" || unitTarget == "SignedTheta" ||
      unitTarget == "InPlaneTwoTheta" || unitTarget == "SignedInPlaneTwoTheta") {
    createThetaMap(progress, unitTarget, inputWS);
  } else if (unitTarget == "ElasticQ" || unitTarget == "ElasticQSquared" || unitTarget == "ElasticDSpacing") {
    createElasticQMap(progress, unitTarget, inputWS);
  }
 
  // Create an output workspace and set the property for it.
  MatrixWorkspace_sptr outputWS = createOutputWorkspace(progress, unitTarget, inputWS);
  setProperty("OutputWorkspace", outputWS);
}
 
void ConvertSpectrumAxis2::createThetaMap(API::Progress &progress, const std::string &targetUnit,
                                          API::MatrixWorkspace_sptr &inputWS) {
  // Not sure about default, previously there was a call to a null function?
  enum thetaTypes { theta, signedTheta, inPlaneTheta, signedInPlaneTheta };
  thetaTypes thetaType = theta;
  if (targetUnit == "signed_theta" || targetUnit == "SignedTheta") {
    thetaType = signedTheta;
  } else if (targetUnit == "theta" || targetUnit == "Theta") {
    thetaType = theta;
  } else if (targetUnit == "InPlaneTwoTheta") {
    thetaType = inPlaneTheta;
  } else if (targetUnit == "SignedInPlaneTwoTheta") {
    thetaType = signedInPlaneTheta;
  }
  bool warningGiven = false;
 
  const auto &spectrumInfo = inputWS->spectrumInfo();
  for (size_t i = 0; i < spectrumInfo.size(); ++i) {
    if (!spectrumInfo.hasDetectors(i)) {
      if (!warningGiven)
        g_log.warning("The instrument definition is incomplete - spectra "
                      "dropped from output");
      warningGiven = true;
      continue;
    }
    if (!spectrumInfo.isMonitor(i)) {
      switch (thetaType) {
      case signedTheta:
        emplaceIndexMap(spectrumInfo.signedTwoTheta(i) * rad2deg, i);
        break;
      case theta:
        emplaceIndexMap(spectrumInfo.twoTheta(i) * rad2deg, i);
        break;
      case inPlaneTheta:
        emplaceIndexMap(inPlaneTwoTheta(i, inputWS) * rad2deg, i);
        break;
      case signedInPlaneTheta:
        emplaceIndexMap(signedInPlaneTwoTheta(i, inputWS) * rad2deg, i);
        break;
      }
    } else {
      emplaceIndexMap(0.0, i);
    }
 
    progress.report("Converting to theta...");
  }
}
 
double ConvertSpectrumAxis2::inPlaneTwoTheta(const size_t index, const API::MatrixWorkspace_sptr &inputWS) const {
  const auto spectrumInfo = inputWS->spectrumInfo();
  const auto refFrame = inputWS->getInstrument()->getReferenceFrame();
  const V3D position = spectrumInfo.position(index) - spectrumInfo.samplePosition();
 
  double angle =
      std::atan2(std::abs(position[refFrame->pointingHorizontal()]), position[refFrame->pointingAlongBeam()]);
  return angle;
}
 
double ConvertSpectrumAxis2::signedInPlaneTwoTheta(const size_t index, const API::MatrixWorkspace_sptr &inputWS) const {
  const auto spectrumInfo = inputWS->spectrumInfo();
  const auto refFrame = inputWS->getInstrument()->getReferenceFrame();
 
  const auto samplePos = spectrumInfo.samplePosition();
  const auto beamLine = samplePos - spectrumInfo.sourcePosition();
 
  if (beamLine.nullVector()) {
    throw Kernel::Exception::InstrumentDefinitionError("Source and sample are at same position!");
  }
 
  const V3D sampleDetVec = spectrumInfo.position(index) - samplePos;
 
  return std::atan2(sampleDetVec[refFrame->pointingHorizontal()], sampleDetVec[refFrame->pointingAlongBeam()]);
}
 
void ConvertSpectrumAxis2::createElasticQMap(API::Progress &progress, const std::string &targetUnit,
                                             API::MatrixWorkspace_sptr &inputWS) {
 
  const std::string emodeStr = getProperty("EMode");
  int emode = 0;
  if (emodeStr == "Direct")
    emode = 1;
  else if (emodeStr == "Indirect")
    emode = 2;
 
  const auto &spectrumInfo = inputWS->spectrumInfo();
  const auto &componentInfo = inputWS->componentInfo();
  const size_t nHist = spectrumInfo.size();
  for (size_t i = 0; i < nHist; i++) {
    double theta(0.0), efixed(0.0);
    if (!spectrumInfo.isMonitor(i)) {
      theta = 0.5 * spectrumInfo.twoTheta(i);
      /*
       * Two assumptions made in the following code.
       * 1. Getting the detector index of the first detector in the spectrum
       * definition is enough (this should be completely safe).
       * 2. That the time index is not important (first element of pair only
       * accessed). i.e we are not performing scanning. Step scanning is not
       * supported at the time of writing.
       */
      const auto detectorIndex = spectrumInfo.spectrumDefinition(i)[0].first;
      efixed = getEfixed(detectorIndex, componentInfo, *inputWS,
                         emode); // get efixed
    } else {
      theta = DBL_MIN;
      efixed = DBL_MIN;
    }
 
    // Convert to MomentumTransfer
    double elasticQInAngstroms = Kernel::UnitConversion::convertToElasticQ(theta, efixed);
 
    if (targetUnit == "ElasticQ") {
      emplaceIndexMap(elasticQInAngstroms, i);
    } else if (targetUnit == "ElasticQSquared") {
      // The QSquared value.
      double elasticQSquaredInAngstroms = elasticQInAngstroms * elasticQInAngstroms;
 
      emplaceIndexMap(elasticQSquaredInAngstroms, i);
    } else if (targetUnit == "ElasticDSpacing") {
      double elasticDSpacing = 2 * M_PI / elasticQInAngstroms;
      emplaceIndexMap(elasticDSpacing, i);
    }
 
    progress.report("Converting to " + targetUnit);
  }
}
 
MatrixWorkspace_sptr ConvertSpectrumAxis2::createOutputWorkspace(API::Progress &progress, const std::string &targetUnit,
                                                                 API::MatrixWorkspace_sptr &inputWS) {
 
  MatrixWorkspace_sptr outputWorkspace = nullptr;
  std::unique_ptr<NumericAxis> newAxis = nullptr;
  EventWorkspace_sptr eventWS = std::dynamic_pointer_cast<EventWorkspace>(inputWS);
  if (m_toOrder) {
    // Can not re-use the input one because the spectra are re-ordered.
    const Histogram hist = eventWS ? Histogram(inputWS->binEdges(0)) : inputWS->histogram(0);
    outputWorkspace = create<MatrixWorkspace>(*inputWS, m_indexMap.size(), hist);
    std::vector<double> axis;
    axis.reserve(m_indexMap.size());
    std::transform(m_indexMap.begin(), m_indexMap.end(), std::back_inserter(axis),
                   [](const auto &it) { return it.first; });
 
    newAxis = std::make_unique<NumericAxis>(std::move(axis));
  } else {
    // If there is no reordering we can simply clone.
    outputWorkspace = inputWS->clone();
    newAxis = std::make_unique<NumericAxis>(m_axis);
  }
 
  // Set the units of the axis.
  if (targetUnit == "theta" || targetUnit == "Theta" || targetUnit == "signed_theta" || targetUnit == "SignedTheta" ||
      targetUnit == "InPlaneTwoTheta" || targetUnit == "SignedInPlaneTwoTheta") {
    newAxis->unit() = std::make_shared<Units::Degrees>();
  } else if (targetUnit == "ElasticQ") {
    newAxis->unit() = UnitFactory::Instance().create("MomentumTransfer");
  } else if (targetUnit == "ElasticQSquared") {
    newAxis->unit() = UnitFactory::Instance().create("QSquared");
  } else if (targetUnit == "ElasticDSpacing") {
    newAxis->unit() = UnitFactory::Instance().create("dSpacing");
  }
  outputWorkspace->replaceAxis(1, std::move(newAxis));
  // Note that this is needed only for ordered case
  if (m_toOrder) {
    size_t currentIndex = 0;
    std::multimap<double, size_t>::const_iterator it;
    for (it = m_indexMap.begin(); it != m_indexMap.end(); ++it) {
      // Copy over the data.
      outputWorkspace->getSpectrum(currentIndex).copyDataFrom(inputWS->getSpectrum(it->second));
      // We can keep the spectrum numbers etc.
      outputWorkspace->getSpectrum(currentIndex).copyInfoFrom(inputWS->getSpectrum(it->second));
      ++currentIndex;
      progress.report("Setting output spectrum #" + std::to_string(currentIndex));
    }
  }
 
  return outputWorkspace;
}
 
double ConvertSpectrumAxis2::getEfixed(const size_t detectorIndex, const Geometry::ComponentInfo &componentInfo,
                                       const Mantid::API::MatrixWorkspace &inputWS, const int emode) const {
  double efixed(0);
  double efixedProp = getProperty("Efixed");
  if (efixedProp != EMPTY_DBL()) {
    efixed = efixedProp;
    g_log.debug() << "Detector index: " << detectorIndex << " Efixed: " << efixed << "\n";
  } else {
    if (emode == 1) {
      if (inputWS.run().hasProperty("Ei")) {
        efixed = inputWS.run().getLogAsSingleValue("Ei");
      } else {
        throw std::invalid_argument("Could not retrieve Efixed from the "
                                    "workspace. Please provide a value.");
      }
    } else if (emode == 2) {
      std::vector<double> efixedVec = componentInfo.getNumberParameter(detectorIndex, "Efixed");
 
      if (!efixedVec.empty()) {
        efixed = efixedVec.at(0);
        g_log.debug() << "Detector index: " << detectorIndex << " EFixed: " << efixed << "\n";
      } else {
        g_log.warning() << "Efixed could not be found for detector with index " << detectorIndex
                        << ", please provide a value\n";
        throw std::invalid_argument("Could not retrieve Efixed from the "
                                    "detector. Please provide a value.");
      }
    }
  }
  return efixed;
}
 
void ConvertSpectrumAxis2::emplaceIndexMap(double value, size_t wsIndex) {
  if (m_toOrder) {
    m_indexMap.emplace(value, wsIndex);
  } else {
    m_axis.emplace_back(value);
  }
}
 
} // namespace Mantid::Algorithms