/**
* @brief Extract Q values from vertical dimension of the workspace, or compute
* them.
* @param workspace workspace possibly containing Q values.
*/
std::vector<double> FunctionQDepends::extractQValues(
const Mantid::API::MatrixWorkspace &workspace) {
std::vector<double> qs;
// Check if the vertical axis has units of momentum transfer, then extract Q
// values...
auto axis_ptr =
dynamic_cast<Mantid::API::NumericAxis *>(workspace.getAxis(1));
if (axis_ptr) {
const boost::shared_ptr<Kernel::Unit> &unit_ptr = axis_ptr->unit();
if (unit_ptr->unitID() == "MomentumTransfer") {
qs = axis_ptr->getValues();
}
}
// ...otherwise, compute the momentum transfer for each spectrum, if possible
else {
const auto &spectrumInfo = workspace.spectrumInfo();
size_t numHist = workspace.getNumberHistograms();
for (size_t wi = 0; wi < numHist; wi++) {
if (spectrumInfo.hasDetectors(wi)) {
const auto detID = spectrumInfo.detector(wi).getID();
double efixed = workspace.getEFixed(detID);
double usignTheta = 0.5 * spectrumInfo.twoTheta(wi);
double q = Mantid::Kernel::UnitConversion::convertToElasticQ(usignTheta,
efixed);
qs.push_back(q);
} else {
g_log.debug("Cannot populate Q values from workspace");
qs.clear();
break;
}
}
}
return qs;
}
