MultiplyMD.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 "MantidMDAlgorithms/MultiplyMD.h"
#include "MantidDataObjects/MDBox.h"
#include "MantidDataObjects/MDBoxBase.h"
#include "MantidDataObjects/MDEventFactory.h"
#include "MantidDataObjects/MDEventWorkspace.h"
#include "MantidKernel/System.h"
 
using namespace Mantid::Kernel;
using namespace Mantid::API;
using namespace Mantid::DataObjects;
 
namespace Mantid::MDAlgorithms {
 
// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(MultiplyMD)
 
//----------------------------------------------------------------------------------------------
const std::string MultiplyMD::name() const { return "MultiplyMD"; }
 
int MultiplyMD::version() const { return 1; }
 
//----------------------------------------------------------------------------------------------
 
//----------------------------------------------------------------------------------------------
bool MultiplyMD::commutative() const { return true; }
 
//----------------------------------------------------------------------------------------------
void MultiplyMD::checkInputs() {
  if (m_rhs_event)
    throw std::runtime_error("Cannot multiply by a MDEventWorkspace on the RHS.");
  if (m_lhs_event && !m_rhs_scalar)
    throw std::runtime_error("A MDEventWorkspace can only be multiplied by a scalar.");
}
 
//----------------------------------------------------------------------------------------------
template <typename MDE, size_t nd> void MultiplyMD::execEventScalar(typename MDEventWorkspace<MDE, nd>::sptr ws) {
  // Get the scalar multiplying
  auto scalar = static_cast<float>(m_rhs_scalar->y(0)[0]);
  auto scalarError = static_cast<float>(m_rhs_scalar->e(0)[0]);
  float scalarErrorSquared = scalarError * scalarError;
  float scalarSquared = scalar * scalar;
 
  // Get all the MDBoxes contained
  MDBoxBase<MDE, nd> *parentBox = ws->getBox();
  std::vector<API::IMDNode *> boxes;
  parentBox->getBoxes(boxes, 1000, true);
 
  bool fileBackedTarget(false);
  Kernel::DiskBuffer *dbuff(nullptr);
  if (ws->isFileBacked()) {
    fileBackedTarget = true;
    dbuff = ws->getBoxController()->getFileIO();
  }
 
  for (auto &boxe : boxes) {
    auto *box = dynamic_cast<MDBox<MDE, nd> *>(boxe);
    if (box) {
      typename std::vector<MDE> &events = box->getEvents();
      size_t ic(events.size());
      auto it = events.begin();
      auto it_end = events.end();
      for (; it != it_end; it++) {
        // Multiply weight by a scalar, propagating error
        float oldSignal = it->getSignal();
        float signal = oldSignal * scalar;
        float errorSquared = scalarSquared * it->getErrorSquared() + oldSignal * oldSignal * scalarErrorSquared;
        it->setSignal(signal);
        it->setErrorSquared(errorSquared);
      }
      box->releaseEvents();
      if (fileBackedTarget && ic > 0) {
        Kernel::ISaveable *const pSaver(box->getISaveable());
        dbuff->toWrite(pSaver);
      }
    }
  }
  // Recalculate the totals
  ws->refreshCache();
  // Mark file-backed workspace as dirty
  ws->setFileNeedsUpdating(true);
}
 
//----------------------------------------------------------------------------------------------
void MultiplyMD::execEvent() {
  if (m_lhs_event && !m_rhs_scalar)
    throw std::runtime_error("A MDEventWorkspace can only be multiplied by a scalar.");
  if (!m_out_event)
    throw std::runtime_error("MultiplyMD::execEvent(): Error creating output MDEventWorkspace.");
  // Call the method to do the multiplying
  CALL_MDEVENT_FUNCTION(this->execEventScalar, m_out_event);
}
 
//----------------------------------------------------------------------------------------------
void MultiplyMD::execHistoHisto(Mantid::DataObjects::MDHistoWorkspace_sptr out,
                                Mantid::DataObjects::MDHistoWorkspace_const_sptr operand) {
  out->multiply(*operand);
}
 
//----------------------------------------------------------------------------------------------
void MultiplyMD::execHistoScalar(Mantid::DataObjects::MDHistoWorkspace_sptr out,
                                 Mantid::DataObjects::WorkspaceSingleValue_const_sptr scalar) {
  out->multiply(scalar->y(0)[0], scalar->e(0)[0]);
}
 
} // namespace Mantid::MDAlgorithms