/**
* A map detector ID and Q ranges
* This method looks unnecessary as it could be calculated on the fly but
* the parallelization means that lazy instantation slows it down due to the
* necessary CRITICAL sections required to update the cache. The Q range
* values are required very frequently so the total time is more than
* offset by this precaching step
*/
void SofQW2::initQCache(API::MatrixWorkspace_const_sptr workspace)
{
Mantid::Kernel::Timer clock;
const size_t nhist(workspace->getNumberHistograms());
const size_t nxpoints = workspace->blocksize();
const MantidVec & X = workspace->readX(0);
m_qcached.clear();
PARALLEL_FOR1(workspace)
for(int64_t i = 0 ; i < (int64_t)nhist; ++i)
{
PARALLEL_START_INTERUPT_REGION
IDetector_const_sptr det;
try
{
det = workspace->getDetector(i);
if( det->isMonitor() ) det.reset();
}
catch(Kernel::Exception::NotFoundError&)
{
// Catch if no detector. Next line tests whether this happened - test placed
// outside here because Mac Intel compiler doesn't like 'continue' in a catch
// in an openmp block.
}
// If no detector found, skip onto the next spectrum
if ( !det ) continue;
std::vector<QValues> qvalues(nxpoints);
DetectorGroup_const_sptr detGroup = boost::dynamic_pointer_cast<const DetectorGroup>(det);
if( detGroup )
{
std::vector<IDetector_const_sptr> dets = detGroup->getDetectors();
const size_t ndets(dets.size());
for( size_t j = 0; j < ndets; ++j )
{
IDetector_const_sptr det_j = dets[j];
QRangeCache qrange(static_cast<size_t>(i), 1.0/(double)ndets);
for( size_t k = 0; k < nxpoints; ++k)
{
qvalues[k] = calculateQValues(det_j, X[k], X[k+1]);
}
qrange.qValues = qvalues;
PARALLEL_CRITICAL(qcache_a)
{
m_qcached.insert(m_qcached.end(), qrange);
}
}
}
else
{
QRangeCache qrange(static_cast<size_t>(i), 1.0);
for( size_t k = 0; k < nxpoints; ++k)
{
qvalues[k] = calculateQValues(det, X[k], X[k+1]);
}
qrange.qValues = qvalues;
PARALLEL_CRITICAL(qcache_b)
{
m_qcached.insert(m_qcached.end(), qrange);
}
}
PARALLEL_END_INTERUPT_REGION
}
void SofQWCentre::exec() {
using namespace Geometry;
MatrixWorkspace_const_sptr inputWorkspace = getProperty("InputWorkspace");
// Do the full check for common binning
if (!WorkspaceHelpers::commonBoundaries(*inputWorkspace)) {
g_log.error(
"The input workspace must have common binning across all spectra");
throw std::invalid_argument(
"The input workspace must have common binning across all spectra");
}
std::vector<double> verticalAxis;
MatrixWorkspace_sptr outputWorkspace = setUpOutputWorkspace(
inputWorkspace, getProperty("QAxisBinning"), verticalAxis);
setProperty("OutputWorkspace", outputWorkspace);
// Holds the spectrum-detector mapping
std::vector<specnum_t> specNumberMapping;
std::vector<detid_t> detIDMapping;
m_EmodeProperties.initCachedValues(*inputWorkspace, this);
int emode = m_EmodeProperties.m_emode;
// Get a pointer to the instrument contained in the workspace
Instrument_const_sptr instrument = inputWorkspace->getInstrument();
// Get the distance between the source and the sample (assume in metres)
IComponent_const_sptr source = instrument->getSource();
IComponent_const_sptr sample = instrument->getSample();
V3D beamDir = sample->getPos() - source->getPos();
beamDir.normalize();
try {
double l1 = source->getDistance(*sample);
g_log.debug() << "Source-sample distance: " << l1 << '\n';
} catch (Exception::NotFoundError &) {
g_log.error("Unable to calculate source-sample distance");
throw Exception::InstrumentDefinitionError(
"Unable to calculate source-sample distance",
inputWorkspace->getTitle());
}
// Conversion constant for E->k. k(A^-1) = sqrt(energyToK*E(meV))
const double energyToK = 8.0 * M_PI * M_PI * PhysicalConstants::NeutronMass *
PhysicalConstants::meV * 1e-20 /
(PhysicalConstants::h * PhysicalConstants::h);
// Loop over input workspace bins, reassigning data to correct bin in output
// qw workspace
const size_t numHists = inputWorkspace->getNumberHistograms();
const size_t numBins = inputWorkspace->blocksize();
Progress prog(this, 0.0, 1.0, numHists);
for (int64_t i = 0; i < int64_t(numHists); ++i) {
try {
// Now get the detector object for this histogram
IDetector_const_sptr spectrumDet = inputWorkspace->getDetector(i);
if (spectrumDet->isMonitor())
continue;
const double efixed = m_EmodeProperties.getEFixed(*spectrumDet);
// For inelastic scattering the simple relationship q=4*pi*sinTheta/lambda
// does not hold. In order to
// be completely general we must calculate the momentum transfer by
// calculating the incident and final
// wave vectors and then use |q| = sqrt[(ki - kf)*(ki - kf)]
DetectorGroup_const_sptr detGroup =
boost::dynamic_pointer_cast<const DetectorGroup>(spectrumDet);
std::vector<IDetector_const_sptr> detectors;
if (detGroup) {
detectors = detGroup->getDetectors();
} else {
detectors.push_back(spectrumDet);
}
const size_t numDets = detectors.size();
// cache to reduce number of static casts
const double numDets_d = static_cast<double>(numDets);
const auto &Y = inputWorkspace->y(i);
const auto &E = inputWorkspace->e(i);
const auto &X = inputWorkspace->x(i);
// Loop over the detectors and for each bin calculate Q
for (size_t idet = 0; idet < numDets; ++idet) {
IDetector_const_sptr det = detectors[idet];
// Calculate kf vector direction and then Q for each energy bin
V3D scatterDir = (det->getPos() - sample->getPos());
scatterDir.normalize();
for (size_t j = 0; j < numBins; ++j) {
const double deltaE = 0.5 * (X[j] + X[j + 1]);
// Compute ki and kf wave vectors and therefore q = ki - kf
double ei(0.0), ef(0.0);
if (emode == 1) {
ei = efixed;
ef = efixed - deltaE;
if (ef < 0) {
std::string mess =
"Energy transfer requested in Direct mode exceeds incident "
"energy.\n Found for det ID: " +
std::to_string(idet) + " bin No " + std::to_string(j) +
" with Ei=" + boost::lexical_cast<std::string>(efixed) +
" and energy transfer: " +
boost::lexical_cast<std::string>(deltaE);
throw std::runtime_error(mess);
}
} else {
ei = efixed + deltaE;
ef = efixed;
if (ef < 0) {
std::string mess =
"Incident energy of a neutron is negative. Are you trying to "
"process Direct data in Indirect mode?\n Found for det ID: " +
std::to_string(idet) + " bin No " + std::to_string(j) +
" with efied=" + boost::lexical_cast<std::string>(efixed) +
" and energy transfer: " +
boost::lexical_cast<std::string>(deltaE);
throw std::runtime_error(mess);
}
}
if (ei < 0)
throw std::runtime_error(
"Negative incident energy. Check binning.");
const V3D ki = beamDir * sqrt(energyToK * ei);
const V3D kf = scatterDir * (sqrt(energyToK * (ef)));
const double q = (ki - kf).norm();
// Test whether it's in range of the Q axis
if (q < verticalAxis.front() || q > verticalAxis.back())
continue;
// Find which q bin this point lies in
const MantidVec::difference_type qIndex =
std::upper_bound(verticalAxis.begin(), verticalAxis.end(), q) -
verticalAxis.begin() - 1;
// Add this spectra-detector pair to the mapping
specNumberMapping.push_back(
outputWorkspace->getSpectrum(qIndex).getSpectrumNo());
detIDMapping.push_back(det->getID());
// And add the data and it's error to that bin, taking into account
// the number of detectors contributing to this bin
outputWorkspace->mutableY(qIndex)[j] += Y[j] / numDets_d;
// Standard error on the average
outputWorkspace->mutableE(qIndex)[j] =
sqrt((pow(outputWorkspace->e(qIndex)[j], 2) + pow(E[j], 2)) /
numDets_d);
}
}
} catch (Exception::NotFoundError &) {
// Get to here if exception thrown when calculating distance to detector
// Presumably, if we get to here the spectrum will be all zeroes anyway
// (from conversion to E)
continue;
}
prog.report();
}
// If the input workspace was a distribution, need to divide by q bin width
if (inputWorkspace->isDistribution())
this->makeDistribution(outputWorkspace, verticalAxis);
// Set the output spectrum-detector mapping
SpectrumDetectorMapping outputDetectorMap(specNumberMapping, detIDMapping);
outputWorkspace->updateSpectraUsing(outputDetectorMap);
// Replace any NaNs in outputWorkspace with zeroes
if (this->getProperty("ReplaceNaNs")) {
auto replaceNans = this->createChildAlgorithm("ReplaceSpecialValues");
replaceNans->setChild(true);
replaceNans->initialize();
replaceNans->setProperty("InputWorkspace", outputWorkspace);
replaceNans->setProperty("OutputWorkspace", outputWorkspace);
replaceNans->setProperty("NaNValue", 0.0);
replaceNans->setProperty("InfinityValue", 0.0);
replaceNans->setProperty("BigNumberThreshold", DBL_MAX);
replaceNans->execute();
}
}
