/** Forms the quadrature phase signal (squashogram)
* @param ws :: [input] workspace containing the measured spectra
* @param phase :: [input] table workspace containing the detector phases
* @param n0 :: [input] vector containing the normalization constants
* @return :: workspace containing the quadrature phase signal
*/
API::MatrixWorkspace_sptr
PhaseQuadMuon::squash(const API::MatrixWorkspace_sptr &ws,
const API::ITableWorkspace_sptr &phase,
const std::vector<double> &n0) {
// Poisson limit: below this number we consider we don't have enough
// statistics
// to apply sqrt(N). This is an arbitrary number used in the original code
// provided by scientists
double poissonLimit = 30.;
size_t nspec = ws->getNumberHistograms();
size_t npoints = ws->blocksize();
// Muon life time in microseconds
double muLife = PhysicalConstants::MuonLifetime * 1e6;
if (n0.size() != nspec) {
throw std::invalid_argument("Invalid normalization constants");
}
// Get the maximum asymmetry
double maxAsym = 0.;
for (size_t h = 0; h < nspec; h++) {
if (phase->Double(h, 1) > maxAsym) {
maxAsym = phase->Double(h, 1);
}
}
if (maxAsym == 0.0) {
throw std::invalid_argument("Invalid detector asymmetries");
}
std::vector<double> aj, bj;
{
// Calculate coefficients aj, bj
double sxx = 0;
double syy = 0;
double sxy = 0;
for (size_t h = 0; h < nspec; h++) {
double asym = phase->Double(h, 1) / maxAsym;
double phi = phase->Double(h, 2);
double X = n0[h] * asym * cos(phi);
double Y = n0[h] * asym * sin(phi);
sxx += X * X;
syy += Y * Y;
sxy += X * Y;
}
double lam1 = 2 * syy / (sxx * syy - sxy * sxy);
double mu1 = 2 * sxy / (sxy * sxy - sxx * syy);
double lam2 = 2 * sxy / (sxy * sxy - sxx * syy);
double mu2 = 2 * sxx / (sxx * syy - sxy * sxy);
for (size_t h = 0; h < nspec; h++) {
double asym = phase->Double(h, 1) / maxAsym;
double phi = phase->Double(h, 2);
double X = n0[h] * asym * cos(phi);
double Y = n0[h] * asym * sin(phi);
aj.push_back((lam1 * X + mu1 * Y) * 0.5);
bj.push_back((lam2 * X + mu2 * Y) * 0.5);
}
}
// First X value
double X0 = ws->x(0).front();
// Create and populate output workspace
API::MatrixWorkspace_sptr ows = API::WorkspaceFactory::Instance().create(
"Workspace2D", 2, npoints + 1, npoints);
// X
ows->setSharedX(0, ws->sharedX(0));
ows->setSharedX(1, ws->sharedX(0));
// Phase quadrature
auto &realY = ows->mutableY(0);
auto &imagY = ows->mutableY(1);
auto &realE = ows->mutableE(0);
auto &imagE = ows->mutableE(1);
for (size_t i = 0; i < npoints; i++) {
for (size_t h = 0; h < nspec; h++) {
// (X,Y,E) with exponential decay removed
const double X = ws->x(h)[i];
const double Y = ws->y(h)[i] - n0[h] * exp(-(X - X0) / muLife);
const double E = (ws->y(h)[i] > poissonLimit)
? ws->e(h)[i]
: sqrt(n0[h] * exp(-(X - X0) / muLife));
realY[i] += aj[h] * Y;
imagY[i] += bj[h] * Y;
realE[i] += aj[h] * aj[h] * E * E;
imagE[i] += bj[h] * bj[h] * E * E;
}
realE[i] = sqrt(realE[i]);
imagE[i] = sqrt(imagE[i]);
// Regain exponential decay
const double X = ws->getSpectrum(0).x()[i];
const double e = exp(-(X - X0) / muLife);
realY[i] /= e;
imagY[i] /= e;
realE[i] /= e;
imagE[i] /= e;
}
return ows;
}
/** Forms the quadrature phase signal (squashogram)
* @param ws :: [input] workspace containing the measured spectra
* @param phase :: [input] table workspace containing the detector phases
* @param n0 :: [input] vector containing the normalization constants
* @return :: workspace containing the quadrature phase signal
*/
API::MatrixWorkspace_sptr
PhaseQuadMuon::squash(const API::MatrixWorkspace_sptr &ws,
const API::ITableWorkspace_sptr &phase,
const std::vector<double> &n0) {
// Poisson limit: below this number we consider we don't have enough
// statistics
// to apply sqrt(N). This is an arbitrary number used in the original code
// provided by scientists
const double poissonLimit = 30.;
// Muon life time in microseconds
const double muLife = PhysicalConstants::MuonLifetime * 1e6;
const size_t nspec = ws->getNumberHistograms();
if (n0.size() != nspec) {
throw std::invalid_argument("Invalid normalization constants");
}
auto names = phase->getColumnNames();
for (auto &name : names) {
std::transform(name.begin(), name.end(), name.begin(), ::tolower);
}
auto phaseIndex = findName(phaseNames, names);
auto asymmetryIndex = findName(asymmNames, names);
// Get the maximum asymmetry
double maxAsym = 0.;
for (size_t h = 0; h < nspec; h++) {
if (phase->Double(h, asymmetryIndex) > maxAsym &&
phase->Double(h, asymmetryIndex) != ASYMM_ERROR) {
maxAsym = phase->Double(h, asymmetryIndex);
}
}
if (maxAsym == 0.0) {
throw std::invalid_argument("Invalid detector asymmetries");
}
std::vector<bool> emptySpectrum;
emptySpectrum.reserve(nspec);
std::vector<double> aj, bj;
{
// Calculate coefficients aj, bj
double sxx = 0.;
double syy = 0.;
double sxy = 0.;
for (size_t h = 0; h < nspec; h++) {
emptySpectrum.push_back(
std::all_of(ws->y(h).begin(), ws->y(h).end(),
[](double value) { return value == 0.; }));
if (!emptySpectrum[h]) {
const double asym = phase->Double(h, asymmetryIndex) / maxAsym;
const double phi = phase->Double(h, phaseIndex);
const double X = n0[h] * asym * cos(phi);
const double Y = n0[h] * asym * sin(phi);
sxx += X * X;
syy += Y * Y;
sxy += X * Y;
}
}
const double lam1 = 2 * syy / (sxx * syy - sxy * sxy);
const double mu1 = 2 * sxy / (sxy * sxy - sxx * syy);
const double lam2 = 2 * sxy / (sxy * sxy - sxx * syy);
const double mu2 = 2 * sxx / (sxx * syy - sxy * sxy);
for (size_t h = 0; h < nspec; h++) {
if (emptySpectrum[h]) {
aj.push_back(0.0);
bj.push_back(0.0);
} else {
const double asym = phase->Double(h, asymmetryIndex) / maxAsym;
const double phi = phase->Double(h, phaseIndex);
const double X = n0[h] * asym * cos(phi);
const double Y = n0[h] * asym * sin(phi);
aj.push_back((lam1 * X + mu1 * Y) * 0.5);
bj.push_back((lam2 * X + mu2 * Y) * 0.5);
}
}
}
const size_t npoints = ws->blocksize();
// Create and populate output workspace
API::MatrixWorkspace_sptr ows =
API::WorkspaceFactory::Instance().create(ws, 2, npoints + 1, npoints);
// X
ows->setSharedX(0, ws->sharedX(0));
ows->setSharedX(1, ws->sharedX(0));
// Phase quadrature
auto &realY = ows->mutableY(0);
auto &imagY = ows->mutableY(1);
auto &realE = ows->mutableE(0);
auto &imagE = ows->mutableE(1);
const auto xPointData = ws->histogram(0).points();
// First X value
const double X0 = xPointData.front();
// calculate exponential decay outside of the loop
std::vector<double> expDecay = xPointData.rawData();
std::transform(expDecay.begin(), expDecay.end(), expDecay.begin(),
[X0, muLife](double x) { return exp(-(x - X0) / muLife); });
for (size_t i = 0; i < npoints; i++) {
for (size_t h = 0; h < nspec; h++) {
if (!emptySpectrum[h]) {
// (X,Y,E) with exponential decay removed
const double X = ws->x(h)[i];
const double exponential = n0[h] * exp(-(X - X0) / muLife);
const double Y = ws->y(h)[i] - exponential;
const double E =
(ws->y(h)[i] > poissonLimit) ? ws->e(h)[i] : sqrt(exponential);
realY[i] += aj[h] * Y;
imagY[i] += bj[h] * Y;
realE[i] += aj[h] * aj[h] * E * E;
imagE[i] += bj[h] * bj[h] * E * E;
}
}
realE[i] = sqrt(realE[i]);
imagE[i] = sqrt(imagE[i]);
// Regain exponential decay
realY[i] /= expDecay[i];
imagY[i] /= expDecay[i];
realE[i] /= expDecay[i];
imagE[i] /= expDecay[i];
}
// New Y axis label
ows->setYUnit("Asymmetry");
return ows;
}