LoadISISNexusHelper.cpp

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2020 ISIS Rutherford Appleton Laboratory UKRI,
//     NScD Oak Ridge National Laboratory, European Spallation Source
//     & Institut Laue - Langevin
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidDataHandling/LoadISISNexusHelper.h"
#include "MantidAPI/Run.h"
#include "MantidAPI/Sample.h"
namespace {
static constexpr std::size_t RUN_TIME_STRING_LENGTH = 19;
} // namespace
 
namespace Mantid::DataHandling::LoadISISNexusHelper {
 
using namespace API;
using namespace NeXus;
 
int64_t findNumberOfSpectra(const NXEntry &entry, const bool hasVMSBlock) {
 
  if (hasVMSBlock) {
    NXInt nsp1 = entry.openNXInt("isis_vms_compat/NSP1");
    nsp1.load();
    return nsp1[0];
  } else {
    NXClass det_class = entry.openNXGroup("detector_1");
    NXInt spectrum_index = det_class.openNXInt("spectrum_index");
    // Not clear what this variable is, number of detectors or number of
    // detectors + monitors if it is number of detectors, that is just the
    // length of the spectra
    spectrum_index.load();
    return spectrum_index.dim0();
  }
}
 
std::tuple<NXInt, NXInt> findDetectorIDsAndSpectrumNumber(const NXEntry &entry, const bool hasVMSBlock) {
  if (hasVMSBlock) {
    NXInt udet = entry.openNXInt("isis_vms_compat/UDET");
    udet.load();
    NXInt spec = entry.openNXInt("isis_vms_compat/SPEC");
    spec.load();
    return std::make_tuple(udet, spec);
  } else {
    NXClass det_class = entry.openNXGroup("detector_1");
    NXInt spectrum_index = det_class.openNXInt("spectrum_index");
    spectrum_index.load();
    // In the new v2 file there is no UDET variable
    // Setting it to spectrum index assumes a 1 to 1 correspondence between
    // detector id and spectrum number, i.e detector 1 maps to spectrum 1
    // This is typical of a Muon Nexus file, as stated in the Nexus V2
    // specification.
    NXInt udet = spectrum_index;
    NXInt spec = spectrum_index;
    return std::make_tuple(udet, spec);
  }
}
 
void loadSampleGeometry(Sample &sample, const NXEntry &entry, const bool hasVMSBlock) {
 
  if (hasVMSBlock) {
    NXInt spb = entry.openNXInt("isis_vms_compat/SPB");
    // Just load the index we need, not the whole block. The flag is the
    // third value in the array
    spb.load(1, 2);
    int geom_id = spb[0];
    sample.setGeometryFlag(geom_id);
 
    NXFloat rspb = entry.openNXFloat("isis_vms_compat/RSPB");
    // Just load the indices we need, not the whole block. The values start
    // from the 4th onward
    rspb.load(3, 3);
    double thick(rspb[0]);
    double height(rspb[1]);
    double width(rspb[2]);
    sample.setThickness(thick);
    sample.setHeight(height);
    sample.setWidth(width);
 
  } else {
    NXClass sampleEntry = entry.openNXGroup("sample");
    std::string id = sampleEntry.getString("id");
    int geom_id(0);
    if (!id.empty()) {
      geom_id = std::stoi(id);
    }
    sample.setGeometryFlag(geom_id);
 
    double thick = sampleEntry.getFloat("thickness");
    double height = sampleEntry.getFloat("height");
    double width = sampleEntry.getFloat("width");
    sample.setThickness(thick);
    sample.setHeight(height);
    sample.setWidth(width);
  }
}
void loadRunDetails(API::Run &run, const NXEntry &entry, const bool hasVMSBlock) {
 
  // Charge is stored as a float
  double proton_charge = static_cast<double>(entry.getFloat("proton_charge"));
  run.setProtonCharge(proton_charge);
 
  std::string run_num = std::to_string(entry.getInt("run_number"));
  run.addProperty("run_number", run_num);
 
  // End date and time is stored separately in ISO format in the
  // "raw_data1/endtime" class
  NXChar char_data = entry.openNXChar("end_time");
  char_data.load();
 
  std::string end_time_iso = std::string(char_data(), RUN_TIME_STRING_LENGTH);
  run.addProperty("run_end", end_time_iso);
 
  char_data = entry.openNXChar("start_time");
  char_data.load();
 
  std::string start_time_iso = std::string(char_data(), RUN_TIME_STRING_LENGTH);
 
  run.addProperty("run_start", start_time_iso);
 
  // If we have a vms block, load details from there
  if (hasVMSBlock) {
 
    NXClass vms_compat = entry.openNXGroup("isis_vms_compat");
 
    // RPB struct info
    NXInt rpb_int = vms_compat.openNXInt("IRPB");
    rpb_int.load();
    run.addProperty("freq",
                    rpb_int[6]); // 2**k where source frequency = 50 / 2**k
    // Now double data
    NXFloat rpb_dbl = vms_compat.openNXFloat("RRPB");
    rpb_dbl.load();
    run.addProperty("gd_prtn_chrg",
                    static_cast<double>(rpb_dbl[7])); // good proton charge (uA.hour)
    run.addProperty("tot_prtn_chrg",
                    static_cast<double>(rpb_dbl[8])); // total proton charge (uA.hour)
    run.addProperty("goodfrm", rpb_int[9]);           // good frames
    run.addProperty("rawfrm", rpb_int[10]);           // raw frames
    run.addProperty("rb_proposal", rpb_int[21]);      // RB (proposal)
    vms_compat.close();
  } else {
    NXFloat floatData = entry.openNXFloat("duration");
    floatData.load();
    run.addProperty("dur", static_cast<double>(floatData[0]), floatData.attributes("units"), true);
 
    // These variables have changed, gd_prtn_chrg is now proton_charge
    floatData = entry.openNXFloat("proton_charge");
    floatData.load();
    run.addProperty("gd_prtn_chrg", static_cast<double>(floatData[0]), floatData.attributes("units"), true);
    // Total_proton_charge is now proton_charge_raw
    floatData = entry.openNXFloat("proton_charge_raw");
    floatData.load();
    run.addProperty("tot_prtn_chrg", static_cast<double>(floatData[0]), floatData.attributes("units"), true);
 
    auto sourceEntry = entry.openNXGroup("instrument/source");
    if (sourceEntry.containsDataSet("frequency")) {
      run.addProperty("freq", entry.getFloat("instrument/source/frequency"));
    } else {
      // If no entry, assume 50hz source (suggested by Freddie Akeroyd)
      run.addProperty("freq", 50, "Hz", true);
    }
 
    run.addProperty("goodfrm", entry.getInt("good_frames"));
    run.addProperty("rawfrm", entry.getInt("raw_frames"));
    run.addProperty("rb_proposal",
                    entry.getString("experiment_identifier")); // RB (proposal)
  }
}
std::shared_ptr<HistogramData::HistogramX> loadTimeData(const NXEntry &entry) {
  // if neturon file time bins stored in dector_1/time_of_flight
  auto detectorEntry = entry.openNXGroup("detector_1");
  if (detectorEntry.containsDataSet("time_of_flight")) {
    auto timeBins = entry.openNXFloat("detector_1/time_of_flight");
    auto x_length = timeBins.dim0();
    timeBins.load();
    auto timeData = std::make_shared<HistogramData::HistogramX>(timeBins(), timeBins() + x_length);
    return timeData;
  } else { // Muon V2 file
    auto timeBins = entry.openNXFloat("detector_1/raw_time");
    auto x_length = timeBins.dim0();
    timeBins.load();
    auto timeData = std::make_shared<HistogramData::HistogramX>(timeBins(), timeBins() + x_length);
    return timeData;
  }
}
} // namespace Mantid::DataHandling::LoadISISNexusHelper