/**
* Corrects a spectra for the detector efficiency calculated from detector
* information. Gets the detector information and uses this to calculate its
* efficiency
* @param spectraIndex :: index of the spectrum to get the efficiency for
* @throw invalid_argument if the shape of a detector is isn't a cylinder
* aligned along one axis
* @throw runtime_error if the SpectraDetectorMap has not been filled
* @throw NotFoundError if the detector or its gas pressure or wall thickness
* were not found
*/
void He3TubeEfficiency::correctForEfficiency(std::size_t spectraIndex)
{
Geometry::IDetector_const_sptr det = this->inputWS->getDetector(spectraIndex);
if( det->isMonitor() || det->isMasked() )
{
return;
}
const double exp_constant = this->calculateExponential(spectraIndex, det);
const double scale = this->getProperty("ScaleFactor");
Mantid::MantidVec &yout = this->outputWS->dataY(spectraIndex);
Mantid::MantidVec &eout = this->outputWS->dataE(spectraIndex);
// Need the original values so this is not a reference
const Mantid::MantidVec yValues = this->inputWS->readY(spectraIndex);
const Mantid::MantidVec eValues = this->inputWS->readE(spectraIndex);
std::vector<double>::const_iterator yinItr = yValues.begin();
std::vector<double>::const_iterator einItr = eValues.begin();
Mantid::MantidVec::const_iterator xItr = this->inputWS->readX(spectraIndex).begin();
Mantid::MantidVec::iterator youtItr = yout.begin();
Mantid::MantidVec::iterator eoutItr = eout.begin();
for( ; youtItr != yout.end(); ++youtItr, ++eoutItr)
{
const double wavelength = (*xItr + *(xItr + 1)) / 2.0;
const double effcorr = this->detectorEfficiency(exp_constant * wavelength, scale);
*youtItr = (*yinItr) * effcorr;
*eoutItr = (*einItr) * effcorr;
++yinItr; ++einItr;
++xItr;
}
return;
}
/**
* Estimated the FWHM for Gaussian peak fitting
*
*/
void ConvertEmptyToTof::estimateFWHM(const Mantid::MantidVec &spec,
double ¢er, double &sigma,
double &height, double &minX,
double &maxX) {
auto maxValueIt =
std::max_element(spec.begin() + static_cast<size_t>(minX),
spec.begin() + static_cast<size_t>(maxX)); // max value
double maxValue = *maxValueIt;
size_t maxIndex =
std::distance(spec.begin(), maxValueIt); // index of max value
auto minFwhmIt =
std::find_if(MantidVec::const_reverse_iterator(maxValueIt),
MantidVec::const_reverse_iterator(spec.cbegin()),
[maxValue](double value) { return value < 0.5 * maxValue; });
auto maxFwhmIt =
std::find_if(maxValueIt, spec.end(),
[maxValue](double value) { return value < 0.5 * maxValue; });
// double fwhm = thisSpecX[maxFwhmIndex] - thisSpecX[minFwhmIndex + 1];
double fwhm =
static_cast<double>(std::distance(minFwhmIt.base(), maxFwhmIt) + 1);
// parameters for the gaussian peak fit
center = static_cast<double>(maxIndex);
sigma = fwhm;
height = maxValue;
g_log.debug() << "Peak estimate : center=" << center << "\t sigma=" << sigma
<< "\t h=" << height << '\n';
// determination of the range used for the peak definition
size_t ipeak_min = std::max(
std::size_t{0},
maxIndex - static_cast<size_t>(2.5 * static_cast<double>(std::distance(
maxValueIt, maxFwhmIt))));
size_t ipeak_max = std::min(
spec.size(),
maxIndex + static_cast<size_t>(2.5 * static_cast<double>(std::distance(
maxFwhmIt, maxValueIt))));
size_t i_delta_peak = ipeak_max - ipeak_min;
g_log.debug() << "Peak estimate xmin/max: " << ipeak_min - 1 << "\t"
<< ipeak_max + 1 << '\n';
minX = static_cast<double>(ipeak_min - 2 * i_delta_peak);
maxX = static_cast<double>(ipeak_max + 2 * i_delta_peak);
}
