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ConvertEmptyToTof.cpp 18.49 KiB
//----------------------------------------------------------------------
// Includes
//----------------------------------------------------------------------
#include "MantidAlgorithms/ConvertEmptyToTof.h"
#include "MantidAPI/Axis.h"
#include "MantidAPI/ConstraintFactory.h"
#include "MantidAPI/FunctionFactory.h"
#include "MantidAPI/IPeakFunction.h"
#include "MantidAPI/WorkspaceFactory.h"
#include "MantidAPI/WorkspaceUnitValidator.h"
#include "MantidGeometry/Instrument.h"
#include "MantidKernel/ArrayProperty.h"
#include "MantidKernel/BoundedValidator.h"
#include "MantidKernel/UnitFactory.h"
#include <cmath>
#include <map>
#include <numeric> // std::accumulate
#include <utility> // std::pair
namespace Mantid {
namespace Algorithms {
using namespace Kernel;
using namespace API;
// Register the algorithm into the AlgorithmFactory
DECLARE_ALGORITHM(ConvertEmptyToTof)
//----------------------------------------------------------------------------------------------
/// Algorithm's name for identification. @see Algorithm::name
const std::string ConvertEmptyToTof::name() const {
return "ConvertEmptyToTof";
}
/// Algorithm's version for identification. @see Algorithm::version
int ConvertEmptyToTof::version() const { return 1; }
/// Algorithm's category for identification. @see Algorithm::category
const std::string ConvertEmptyToTof::category() const {
return "Transforms\\Units";
}
//----------------------------------------------------------------------------------------------
/** Initialize the algorithm's properties.
*/
void ConvertEmptyToTof::init() {
auto wsValidator = boost::make_shared<WorkspaceUnitValidator>("Empty");
declareProperty(make_unique<WorkspaceProperty<DataObjects::Workspace2D>>(
"InputWorkspace", "", Direction::Input, wsValidator),
"Name of the input workspace");
declareProperty(make_unique<WorkspaceProperty<API::MatrixWorkspace>>(
"OutputWorkspace", "", Direction::Output),
"Name of the output workspace, can be the same as the input");
declareProperty(
make_unique<Kernel::ArrayProperty<int>>("ListOfSpectraIndices"),
"A list of spectra workspace indices as a string with ranges; e.g. "
"5-10,15,20-23. \n"
"Optional: if not specified, then the Start/EndIndex fields "
"are used alone. "
"If specified, the range and the list are combined (without "
"duplicating indices). For example, a range of 10 to 20 and "
"a list '12,15,26,28' gives '10-20,26,28'.");
declareProperty(
make_unique<Kernel::ArrayProperty<int>>("ListOfChannelIndices"),
"A list of spectra indices as a string with ranges; e.g. "
"5-10,15,20-23. \n" "Optional: if not specified, then the Start/EndIndex fields "
"are used alone. "
"If specified, the range and the list are combined (without "
"duplicating indices). For example, a range of 10 to 20 and "
"a list '12,15,26,28' gives '10-20,26,28'.");
// OR Specify EPP
auto mustBePositive = boost::make_shared<BoundedValidator<int>>();
mustBePositive->setLower(0);
declareProperty(
"ElasticPeakPosition", EMPTY_INT(), mustBePositive,
"Value of elastic peak position if none of the above are filled in.");
declareProperty("ElasticPeakPositionSpectrum", EMPTY_INT(), mustBePositive,
"Workspace Index used for elastic peak position above.");
}
//----------------------------------------------------------------------------------------------
/** Execute the algorithm.
*/
void ConvertEmptyToTof::exec() {
m_inputWS = this->getProperty("InputWorkspace");
m_outputWS = this->getProperty("OutputWorkspace");
std::vector<int> spectraIndices = getProperty("ListOfSpectraIndices");
std::vector<int> channelIndices = getProperty("ListOfChannelIndices");
int epp = getProperty("ElasticPeakPosition");
int eppSpectrum = getProperty("ElasticPeakPositionSpectrum");
std::vector<double> tofAxis;
double channelWidth = getPropertyFromRun<double>(m_inputWS, "channel_width");
// If the ElasticPeakPosition and the ElasticPeakPositionSpectrum were
// specified
if (epp != EMPTY_INT() && eppSpectrum != EMPTY_INT()) {
g_log.information("Using the specified ElasticPeakPosition and "
"ElasticPeakPositionSpectrum");
double wavelength = getPropertyFromRun<double>(m_inputWS, "wavelength");
double l1 = getL1(m_inputWS);
double l2 = getL2(m_inputWS, eppSpectrum);
double epTof =
(calculateTOF(l1, wavelength) + calculateTOF(l2, wavelength)) *
1e6; // microsecs
tofAxis = makeTofAxis(epp, epTof, m_inputWS->blocksize() + 1, channelWidth);
}
// If the spectraIndices and channelIndices were specified
else {
// validations
validateWorkspaceIndices(spectraIndices);
validateChannelIndices(channelIndices);
// Map of spectra index, epp
std::map<int, int> eppMap =
findElasticPeakPositions(spectraIndices, channelIndices);
for (auto &epp : eppMap) {
g_log.debug() << "Spectra idx =" << epp.first << ", epp=" << epp.second
<< '\n';
}
std::pair<int, double> eppAndEpTof = findAverageEppAndEpTof(eppMap);
tofAxis = makeTofAxis(eppAndEpTof.first, eppAndEpTof.second,
m_inputWS->blocksize() + 1, channelWidth);
}
// If input and output workspaces are not the same, create a new workspace for // the output
if (m_outputWS != m_inputWS) {
m_outputWS = m_inputWS->clone();
}
setTofInWS(tofAxis, m_outputWS);
setProperty("OutputWorkspace", m_outputWS);
}
/**
* Check if spectra indices are in the limits of the number of histograms
* in the input workspace. If v is empty, uses all spectra.
* @param v :: vector with the spectra indices
*/
void ConvertEmptyToTof::validateWorkspaceIndices(std::vector<int> &v) {
auto nHist = m_inputWS->getNumberHistograms();
if (v.empty()) {
g_log.information(
"No spectrum number given. Using all spectra to calculate "
"the elastic peak.");
// use all spectra indices
v.reserve(nHist);
for (unsigned int i = 0; i < nHist; ++i)
v[i] = i;
} else {
for (auto index : v) {
if (index < 0 || static_cast<size_t>(index) >= nHist) {
throw std::runtime_error("Spectra index out of limits: " +
std::to_string(index));
}
}
}
}
/**
* Check if the channel indices are in the limits of the number of the block
* size
* in the input workspace. If v is empty, uses all channels.
* @param v :: vector with the channel indices to use
*/
void ConvertEmptyToTof::validateChannelIndices(std::vector<int> &v) {
auto blockSize = m_inputWS->blocksize() + 1;
if (v.empty()) {
g_log.information("No channel index given. Using all channels (full "
"spectrum!) to calculate the elastic peak.");
// use all channel indices
v.reserve(blockSize);
for (unsigned int i = 0; i < blockSize; ++i)
v[i] = i;
} else {
for (auto &index : v) {
if (index < 0 || static_cast<size_t>(index) >= blockSize) {
throw std::runtime_error("Channel index out of limits: " +
std::to_string(index));
}
}
}
}
/**
* Looks for the EPP positions in the spectraIndices
* @return map with worskpace spectra index, elastic peak position for this
* spectra
*/
std::map<int, int> ConvertEmptyToTof::findElasticPeakPositions(
const std::vector<int> &spectraIndices,
const std::vector<int> &channelIndices) {
std::map<int, int> eppMap;
// make sure we not looking for channel indices outside the bounds
assert(static_cast<size_t>(*(channelIndices.end() - 1)) <
m_inputWS->blocksize() + 1);
g_log.information() << "Peak detection, search for peak \n";
for (auto spectrumIndex : spectraIndices) {
auto &thisSpecY = m_inputWS->y(spectrumIndex);
int minChannelIndex = *(channelIndices.begin());
int maxChannelIndex = *(channelIndices.end() - 1);
double center, sigma, height, minX, maxX;
minX = static_cast<double>(minChannelIndex);
maxX = static_cast<double>(maxChannelIndex);
estimateFWHM(thisSpecY, center, sigma, height, minX, maxX);
g_log.debug() << "Peak estimate :: center=" << center
<< "\t sigma=" << sigma << "\t height=" << height
<< "\t minX=" << minX << "\t maxX=" << maxX << '\n';
bool doFit =
doFitGaussianPeak(spectrumIndex, center, sigma, height, minX, maxX);
if (!doFit) {
g_log.error() << "doFitGaussianPeak failed...\n";
throw std::runtime_error("Gaussin Peak Fit failed....");
}
g_log.debug() << "Peak Fitting :: center=" << center << "\t sigma=" << sigma
<< "\t height=" << height << "\t minX=" << minX
<< "\t maxX=" << maxX << '\n';
// round up the center to the closest int
eppMap[spectrumIndex] = roundUp(center);
}
return eppMap;
}
/**
* Estimated the FWHM for Gaussian peak fitting
*
*/
void ConvertEmptyToTof::estimateFWHM(
const Mantid::HistogramData::HistogramY &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);
}
/**
* Fit peak without background i.e, with background removed
* inspired from FitPowderDiffPeaks.cpp
* copied from PoldiPeakDetection2.cpp
*
@param workspaceindex :: indice of the row to use
@param center :: gaussian parameter - center
@param sigma :: gaussian parameter - width
@param height :: gaussian parameter - height
@param startX :: fit range - start X value
@param endX :: fit range - end X value
@returns A boolean status flag, true for fit success, false else
*/
bool ConvertEmptyToTof::doFitGaussianPeak(int workspaceindex, double ¢er,
double &sigma, double &height,
double startX, double endX) {
g_log.debug("Calling doFitGaussianPeak...");
// 1. Estimate
sigma = sigma * 0.5;
// 2. Use factory to generate Gaussian
auto temppeak = API::FunctionFactory::Instance().createFunction("Gaussian");
auto gaussianpeak = boost::dynamic_pointer_cast<API::IPeakFunction>(temppeak);
gaussianpeak->setHeight(height);
gaussianpeak->setCentre(center);
gaussianpeak->setFwhm(sigma);
// 3. Constraint
double centerleftend = center - sigma * 0.5;
double centerrightend = center + sigma * 0.5;
std::ostringstream os;
os << centerleftend << " < PeakCentre < " << centerrightend;
auto *centerbound = API::ConstraintFactory::Instance().createInitialized(
gaussianpeak.get(), os.str(), false);
gaussianpeak->addConstraint(centerbound);
g_log.debug("Calling createChildAlgorithm : Fit...");
// 4. Fit
API::IAlgorithm_sptr fitalg = createChildAlgorithm("Fit", -1, -1, true);
fitalg->initialize();
fitalg->setProperty(
"Function", boost::dynamic_pointer_cast<API::IFunction>(gaussianpeak));
fitalg->setProperty("InputWorkspace", m_inputWS);
fitalg->setProperty("WorkspaceIndex", workspaceindex); fitalg->setProperty("Minimizer", "Levenberg-MarquardtMD");
fitalg->setProperty("CostFunction", "Least squares");
fitalg->setProperty("MaxIterations", 1000);
fitalg->setProperty("Output", "FitGaussianPeak");
fitalg->setProperty("StartX", startX);
fitalg->setProperty("EndX", endX);
// 5. Result
bool successfulfit = fitalg->execute();
if (!fitalg->isExecuted() || !successfulfit) {
// Early return due to bad fit
g_log.warning() << "Fitting Gaussian peak for peak around "
<< gaussianpeak->centre() << '\n';
return false;
}
// 6. Get result
center = gaussianpeak->centre();
height = gaussianpeak->height();
double fwhm = gaussianpeak->fwhm();
return fwhm > 0.0;
}
/**
* Finds the TOF for a given epp
* @param eppMap : pair workspace spec index - epp
* @return the average EPP and the corresponding average EP in TOF
*/
std::pair<int, double>
ConvertEmptyToTof::findAverageEppAndEpTof(const std::map<int, int> &eppMap) {
double l1 = getL1(m_inputWS);
double wavelength = getPropertyFromRun<double>(m_inputWS, "wavelength");
std::vector<double> epTofList;
std::vector<int> eppList;
double firstL2 = getL2(m_inputWS, eppMap.begin()->first);
for (const auto &epp : eppMap) {
double l2 = getL2(m_inputWS, epp.first);
if (!areEqual(l2, firstL2, 0.0001)) {
g_log.error() << "firstL2=" << firstL2 << " , "
<< "l2=" << l2 << '\n';
throw std::runtime_error("All the pixels for selected spectra must have "
"the same distance from the sample!");
} else {
firstL2 = l2;
}
epTofList.push_back(
(calculateTOF(l1, wavelength) + calculateTOF(l2, wavelength)) *
1e6); // microsecs
eppList.push_back(epp.first);
g_log.debug() << "WS index = " << epp.first << ", l1 = " << l1
<< ", l2 = " << l2
<< ", TOF(l1+l2) = " << *(epTofList.end() - 1) << '\n';
}
double averageEpTof =
std::accumulate(epTofList.begin(), epTofList.end(), 0.0) /
static_cast<double>(epTofList.size());
int averageEpp = roundUp(
static_cast<double>(std::accumulate(eppList.begin(), eppList.end(), 0)) /
static_cast<double>(eppList.size()));
g_log.debug() << "Average epp=" << averageEpp << " , Average epTof=" << averageEpTof << '\n';
return std::make_pair(averageEpp, averageEpTof);
}
double ConvertEmptyToTof::getL1(API::MatrixWorkspace_const_sptr workspace) {
Geometry::Instrument_const_sptr instrument = workspace->getInstrument();
Geometry::IComponent_const_sptr sample = instrument->getSample();
double l1 = instrument->getSource()->getDistance(*sample);
return l1;
}
double ConvertEmptyToTof::getL2(API::MatrixWorkspace_const_sptr workspace,
int detId) {
// Get a pointer to the instrument contained in the workspace
Geometry::Instrument_const_sptr instrument = workspace->getInstrument();
// Get the distance between the source and the sample (assume in metres)
Geometry::IComponent_const_sptr sample = instrument->getSample();
// Get the sample-detector distance for this detector (in metres)
double l2 =
workspace->getDetector(detId)->getPos().distance(sample->getPos());
return l2;
}
double ConvertEmptyToTof::calculateTOF(double distance, double wavelength) {
if (wavelength <= 0) {
throw std::runtime_error("Wavelenght is <= 0");
}
double velocity = PhysicalConstants::h / (PhysicalConstants::NeutronMass *
wavelength * 1e-10); // m/s
return distance / velocity;
}
/**
* Compare two double with a precision epsilon
*/
bool ConvertEmptyToTof::areEqual(double a, double b, double epsilon) {
return fabs(a - b) < epsilon;
}
template <typename T>
T ConvertEmptyToTof::getPropertyFromRun(API::MatrixWorkspace_const_sptr inputWS,
const std::string &propertyName) {
if (inputWS->run().hasProperty(propertyName)) {
Kernel::Property *prop = inputWS->run().getProperty(propertyName);
return boost::lexical_cast<T>(prop->value());
} else {
std::string mesg =
"No '" + propertyName + "' property found in the input workspace....";
throw std::runtime_error(mesg);
}
}
int ConvertEmptyToTof::roundUp(double value) {
return static_cast<int>(std::floor(value + 0.5));
}
/**
* Builds the X time axis
*/
std::vector<double> ConvertEmptyToTof::makeTofAxis(int epp, double epTof,
size_t size,
double channelWidth) {
std::vector<double> axis(size);
g_log.debug() << "Building the TOF X Axis: epp=" << epp << ", epTof=" << epTof
<< ", Channel Width=" << channelWidth << '\n';
for (size_t i = 0; i < size; ++i) {
axis[i] = epTof + channelWidth * static_cast<double>(static_cast<int>(i) - epp) -
channelWidth /
2; // to make sure the bin is in the middle of the elastic peak
}
g_log.debug() << "TOF X Axis: [start,end] = [" << *axis.begin() << ","
<< *(axis.end() - 1) << "]\n";
return axis;
}
void ConvertEmptyToTof::setTofInWS(const std::vector<double> &tofAxis,
API::MatrixWorkspace_sptr outputWS) {
const size_t numberOfSpectra = m_inputWS->getNumberHistograms();
g_log.debug() << "Setting the TOF X Axis for numberOfSpectra="
<< numberOfSpectra << '\n';
auto axisPtr = Kernel::make_cow<HistogramData::HistogramX>(tofAxis);
HistogramData::BinEdges edges(tofAxis);
Progress prog(this, 0.0, 0.2, numberOfSpectra);
for (size_t i = 0; i < numberOfSpectra; ++i) {
// Replace bin edges with tof axis
outputWS->setBinEdges(i, edges);
prog.report();
} // end for i
outputWS->getAxis(0)->unit() = UnitFactory::Instance().create("TOF");
}
} // namespace Algorithms
} // namespace Mantid