CarpenterSampleCorrection.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/CarpenterSampleCorrection.h"
#include "MantidAPI/InstrumentValidator.h"
#include "MantidAPI/WorkspaceUnitValidator.h"
#include "MantidDataObjects/EventWorkspace.h"
#include "MantidKernel/CompositeValidator.h"
 
#include <stdexcept>
 
namespace Mantid::Algorithms {
DECLARE_ALGORITHM(CarpenterSampleCorrection) // Register the class
                                             // into the algorithm
                                             // factory
 
using namespace Kernel;
using namespace API;
using Mantid::DataObjects::EventWorkspace;
using Mantid::DataObjects::EventWorkspace_sptr;
using namespace Geometry;
 
const std::string CarpenterSampleCorrection::name() const { return "CarpenterSampleCorrection"; }
 
int CarpenterSampleCorrection::version() const { return 1; }
 
const std::string CarpenterSampleCorrection::category() const { return "CorrectionFunctions\\AbsorptionCorrections"; }
 
void CarpenterSampleCorrection::init() {
  // The input workspace must have an instrument and units of wavelength
  auto wsValidator = std::make_shared<CompositeValidator>();
  wsValidator->add<WorkspaceUnitValidator>("Wavelength");
  wsValidator->add<InstrumentValidator>();
 
  auto algCalcCarpenter = AlgorithmManager::Instance().createUnmanaged("CalculateCarpenterSampleCorrection");
  algCalcCarpenter->initialize();
 
  declareProperty(
      std::make_unique<WorkspaceProperty<API::MatrixWorkspace>>("InputWorkspace", "", Direction::Input, wsValidator),
      "The name of the input workspace.");
  declareProperty(std::make_unique<WorkspaceProperty<API::MatrixWorkspace>>("OutputWorkspace", "", Direction::Output),
                  "The name of the output workspace.");
 
  copyProperty(algCalcCarpenter, "AttenuationXSection");
  copyProperty(algCalcCarpenter, "ScatteringXSection");
  copyProperty(algCalcCarpenter, "SampleNumberDensity");
  copyProperty(algCalcCarpenter, "CylinderSampleRadius");
}
 
void CarpenterSampleCorrection::exec() {
  // common information
  MatrixWorkspace_sptr inputWksp = getProperty("InputWorkspace");
  double radius = getProperty("CylinderSampleRadius");
  double coeff1 = getProperty("AttenuationXSection");
  double coeff2 = getProperty("SampleNumberDensity");
  double coeff3 = getProperty("ScatteringXSection");
 
  // Calculate the absorption and multiple scattering corrections
  WorkspaceGroup_sptr calcOutput = calculateCorrection(inputWksp, radius, coeff1, coeff2, coeff3, true, true);
  Workspace_sptr absPtr = calcOutput->getItem(0);
  Workspace_sptr msPtr = calcOutput->getItem(1);
  auto absWksp = std::dynamic_pointer_cast<MatrixWorkspace>(absPtr);
  auto msWksp = std::dynamic_pointer_cast<MatrixWorkspace>(msPtr);
 
  EventWorkspace_sptr inputWkspEvent = std::dynamic_pointer_cast<EventWorkspace>(inputWksp);
 
  // Inverse the absorption correction ( 1/A)
  const auto NUM_HIST = static_cast<int64_t>(inputWksp->getNumberHistograms());
  PARALLEL_FOR_IF(Kernel::threadSafe(*absWksp))
  for (int64_t i = 0; i < NUM_HIST; ++i) {
    PARALLEL_START_INTERRUPT_REGION
    auto &y = absWksp->mutableY(i);
    for (size_t j = 0; j < y.size(); j++) {
      y[j] = 1.0 / y[j];
    }
    PARALLEL_END_INTERRUPT_REGION
  }
  PARALLEL_CHECK_INTERRUPT_REGION
 
  // Compute the overall correction (= 1/A - MS ) to multiply by
  auto correctionWksp = minus(absWksp, msWksp);
 
  // Apply the correction to the sample workspace
  //   = (1/A - MS) * wksp
  //   = wksp/A - MS * wksp
  MatrixWorkspace_sptr outputWksp = multiply(inputWksp, correctionWksp);
 
  // Output workspace
  if (inputWkspEvent) {
    auto outputWkspEvent = std::dynamic_pointer_cast<EventWorkspace>(outputWksp);
    setProperty("OutputWorkspace", outputWkspEvent);
  }
  setProperty("OutputWorkspace", outputWksp);
}
 
WorkspaceGroup_sptr CarpenterSampleCorrection::calculateCorrection(MatrixWorkspace_sptr &inputWksp, double radius,
                                                                   double coeff1, double coeff2, double coeff3,
                                                                   bool doAbs, bool doMS) {
  auto calculate = this->createChildAlgorithm("CalculateCarpenterSampleCorrection", 0.0, 0.25);
  calculate->setProperty("InputWorkspace", inputWksp);
  calculate->setProperty("CylinderSampleRadius", radius);
  calculate->setProperty("AttenuationXSection", coeff1);
  calculate->setProperty("SampleNumberDensity", coeff2);
  calculate->setProperty("ScatteringXSection", coeff3);
  calculate->setProperty("Absorption", doAbs);
  calculate->setProperty("MultipleScattering", doMS);
  calculate->execute();
  WorkspaceGroup_sptr calcOutput = calculate->getProperty("OutputWorkspaceBaseName");
  return calcOutput;
}
 
MatrixWorkspace_sptr CarpenterSampleCorrection::minus(const MatrixWorkspace_sptr &lhsWS,
                                                      const MatrixWorkspace_sptr &rhsWS) {
  auto minus = this->createChildAlgorithm("Minus", 0.5, 0.75);
  minus->setProperty("LHSWorkspace", lhsWS);
  minus->setProperty("RHSWorkspace", rhsWS);
  minus->execute();
  MatrixWorkspace_sptr outWS = minus->getProperty("OutputWorkspace");
  return outWS;
}
 
MatrixWorkspace_sptr CarpenterSampleCorrection::multiply(const MatrixWorkspace_sptr &lhsWS,
                                                         const MatrixWorkspace_sptr &rhsWS) {
  auto multiply = this->createChildAlgorithm("Multiply", 0.75, 1.0);
  multiply->setProperty("LHSWorkspace", lhsWS);
  multiply->setProperty("RHSWorkspace", rhsWS);
  multiply->execute();
  MatrixWorkspace_sptr outWS = multiply->getProperty("OutputWorkspace");
  return outWS;
}
 
} // namespace Mantid::Algorithms