void VesuvioResolution::function1D(double *out, const double *xValues,
const size_t nData) const {
std::vector<double> outVec(static_cast<int>(nData), 0);
const std::vector<double> xValuesVec(xValues, xValues + nData);
voigtApprox(outVec, xValuesVec, 0, 1, m_lorentzFWHM, m_resolutionSigma);
std::copy(outVec.begin(), outVec.end(), out);
}
/**
* Convenience wrapper for voigtApprox. This version uses the cached values of
* the widths
* @param voigt [Out] Output values (vector is expected to be of the correct
* size
* @param xValues Input coordinates
* @param lorentzPos LorentzPos parameter
* @param lorentzAmp LorentzAmp parameter
*/
void VesuvioResolution::voigtApprox(std::vector<double> &voigt,
const std::vector<double> &xValues,
const double lorentzPos,
const double lorentzAmp) const {
voigtApprox(voigt, xValues, lorentzPos, lorentzAmp, m_lorentzFWHM,
m_resolutionSigma);
}
/**
* Uses a Gaussian approximation for the mass and convolutes it with the Voigt
* instrument resolution function
* @param result An pre-sized output vector that should be filled with the results
* @param lorentzFWHM The lorentz width for the resolution
* @param resolutionFWHM The sum-squared value of the resolution errors
*/
void GaussianComptonProfile::massProfile(std::vector<double> & result,const double lorentzFWHM, const double resolutionFWHM) const
{
double lorentzPos(0.0), gaussWidth(getParameter(0)), amplitude(getParameter(1));
double gaussFWHM = std::sqrt(std::pow(resolutionFWHM,2) + std::pow(2.0*STDDEV_TO_HWHM*gaussWidth,2));
const auto & yspace = ySpace();
// Gaussian already folded into Voigt
voigtApprox(result, yspace, lorentzPos, amplitude, lorentzFWHM, gaussFWHM);
std::vector<double> voigtDiffResult(yspace.size());
voigtApproxDiff(voigtDiffResult, yspace, lorentzPos, amplitude, lorentzFWHM, gaussFWHM);
const auto & modq = modQ();
const size_t nData(result.size());
for(size_t j = 0; j < nData; ++j)
{
const double factor = std::pow(gaussWidth,4.0)/(3.0*modq[j]);
result[j] -= factor*voigtDiffResult[j];
}
}
