PawleyFunction.cpp

// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2018 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidCurveFitting/Functions/PawleyFunction.h"

#include "MantidAPI/Axis.h"
#include "MantidAPI/FunctionFactory.h"
#include "MantidAPI/MatrixWorkspace.h"

#include "MantidCurveFitting/Constraints/BoundaryConstraint.h"

#include "MantidKernel/ConfigService.h"
#include "MantidKernel/UnitConversion.h"
#include "MantidKernel/UnitFactory.h"

#include <boost/algorithm/string.hpp>
#include <memory>

namespace Mantid::CurveFitting::Functions {

using namespace CurveFitting;
using namespace Constraints;

DECLARE_FUNCTION(PawleyParameterFunction)

using namespace API;

using namespace Geometry;

using namespace Kernel;

/// Constructor
PawleyParameterFunction::PawleyParameterFunction()
    : ParamFunction(), m_latticeSystem(PointGroup::LatticeSystem::Triclinic), m_profileFunctionCenterParameterName() {}

/**
 * @brief Sets the supplied attribute value
 *
 * The function calls ParamFunction::setAttribute, but performs additional
 * actions for latticeSystem and ProfileFunction.
 *
 * @param attName :: Name of the attribute
 * @param attValue :: Value of the attribute
 */
void PawleyParameterFunction::setAttribute(const std::string &attName, const Attribute &attValue) {
  if (attName == "LatticeSystem") {
    setLatticeSystem(attValue.asString());
  } else if (attName == "ProfileFunction") {
    setProfileFunction(attValue.asString());
  }

  ParamFunction::setAttribute(attName, attValue);
}

/// Returns the crystal system
PointGroup::LatticeSystem PawleyParameterFunction::getLatticeSystem() const { return m_latticeSystem; }

/// Returns a UnitCell object constructed from the function's parameters.
UnitCell PawleyParameterFunction::getUnitCellFromParameters() const {
  switch (m_latticeSystem) {
  case PointGroup::LatticeSystem::Cubic: {
    double a = getParameter("a");
    double aErr = getError(0);
    UnitCell uc(a, a, a);
    uc.setError(aErr, aErr, aErr, 0.0, 0.0, 0.0);
    return uc;
  }
  case PointGroup::LatticeSystem::Tetragonal: {
    double a = getParameter("a");
    double aErr = getError(0);
    UnitCell uc(a, a, getParameter("c"));
    uc.setError(aErr, aErr, getError(1), 0.0, 0.0, 0.0);
    return uc;
  }
  case PointGroup::LatticeSystem::Hexagonal: {
    double a = getParameter("a");
    double aErr = getError(0);
    UnitCell uc(a, a, getParameter("c"), 90, 90, 120);
    uc.setError(aErr, aErr, getError(1), 0.0, 0.0, 0.0);
    return uc;
  }
  case PointGroup::LatticeSystem::Rhombohedral: {
    double a = getParameter("a");
    double alpha = getParameter("Alpha");
    double aErr = getError(0);
    double alphaErr = getError(1);
    UnitCell uc(a, a, a, alpha, alpha, alpha);
    uc.setError(aErr, aErr, aErr, alphaErr, alphaErr, alphaErr);
    return uc;
  }
  case PointGroup::LatticeSystem::Orthorhombic: {
    UnitCell uc(getParameter("a"), getParameter("b"), getParameter("c"));
    uc.setError(getError(0), getError(1), getError(2), 0.0, 0.0, 0.0);
    return uc;
  }
  case PointGroup::LatticeSystem::Monoclinic: {
    UnitCell uc(getParameter("a"), getParameter("b"), getParameter("c"), 90, getParameter("Beta"), 90);
    uc.setError(getError(0), getError(1), getError(2), 0.0, getError(3), 0.0);
    return uc;
  }
  case PointGroup::LatticeSystem::Triclinic: {
    UnitCell uc(getParameter("a"), getParameter("b"), getParameter("c"), getParameter("Alpha"), getParameter("Beta"),
                getParameter("Gamma"));
    uc.setError(getError(0), getError(1), getError(2), getError(3), getError(4), getError(5));
    return uc;
  }
  }

  return UnitCell();
}

/// Sets the function's parameters from the supplied UnitCell.
void PawleyParameterFunction::setParametersFromUnitCell(const UnitCell &cell) {
  // Parameter "a" exists in all crystal systems.
  setParameter("a", cell.a());

  try {
    setParameter("b", cell.b());
  } catch (const std::invalid_argument &) {
    // do nothing.
  }

  try {
    setParameter("c", cell.c());
  } catch (const std::invalid_argument &) {
    // do nothing
  }

  try {
    setParameter("Alpha", cell.alpha());
  } catch (const std::invalid_argument &) {
    // do nothing.
  }
  try {
    setParameter("Beta", cell.beta());
  } catch (const std::invalid_argument &) {
    // do nothing.
  }
  try {
    setParameter("Gamma", cell.gamma());
  } catch (const std::invalid_argument &) {
    // do nothing.
  }
}

/// This method does nothing.
void PawleyParameterFunction::function(const FunctionDomain &domain, FunctionValues &values) const {
  UNUSED_ARG(domain);
  UNUSED_ARG(values);
}

/// This method does nothing.
void PawleyParameterFunction::functionDeriv(const FunctionDomain &domain, Jacobian &jacobian) {
  UNUSED_ARG(domain)
  UNUSED_ARG(jacobian);
}

/// Declares attributes and generates parameters based on the defaults.
void PawleyParameterFunction::init() {
  declareAttribute("LatticeSystem", IFunction::Attribute("Triclinic"));
  declareAttribute("ProfileFunction", IFunction::Attribute("Gaussian"));

  setLatticeSystem("Triclinic");
  setProfileFunction("Gaussian");
}

/**
 * Sets the profile function
 *
 * This method takes a function name and tries to create the corresponding
 * function through FunctionFactory. Then it checks whether the function
 * inherits from IPeakFunction and determines the centre parameter to store it.
 *
 * @param profileFunction :: Name of an IPeakFunction implementation.
 */
void PawleyParameterFunction::setProfileFunction(const std::string &profileFunction) {
  IPeakFunction_sptr peakFunction =
      std::dynamic_pointer_cast<IPeakFunction>(FunctionFactory::Instance().createFunction(profileFunction));

  if (!peakFunction) {
    throw std::invalid_argument("PawleyFunction can only use IPeakFunctions to "
                                "calculate peak profiles.");
  }

  setCenterParameterNameFromFunction(peakFunction);
}

/**
 * Assigns the lattice system
 *
 * This method takes the name of a lattice system (case insensitive) and stores
 * it. Furthermore it creates the necessary parameters, which means that after
 * calling this function, PawleyParameterFunction potentially exposes a
 * different number of parameters. The parameters are constrained to physically
 * meaningful values (angles between 0 and 180 degrees, cell edges above 0).
 *
 * @param latticeSystem :: Crystal system, case insensitive.
 */
void PawleyParameterFunction::setLatticeSystem(const std::string &latticeSystem) {
  m_latticeSystem = Geometry::getLatticeSystemFromString(latticeSystem);

  createLatticeSystemParameters(m_latticeSystem);
}

/// This method clears all parameters and declares parameters according to the
/// supplied crystal system.
void PawleyParameterFunction::createLatticeSystemParameters(PointGroup::LatticeSystem latticeSystem) {

  clearAllParameters();
  switch (latticeSystem) {
  case PointGroup::LatticeSystem::Cubic:
    declareParameter("a", 1.0);
    addLengthConstraint("a");
    break;

  case PointGroup::LatticeSystem::Hexagonal:
  case PointGroup::LatticeSystem::Tetragonal:
    declareParameter("a", 1.0);
    declareParameter("c", 1.0);
    addLengthConstraint("a");
    addLengthConstraint("c");
    break;

  case PointGroup::LatticeSystem::Orthorhombic:
    declareParameter("a", 1.0);
    declareParameter("b", 1.0);
    declareParameter("c", 1.0);
    addLengthConstraint("a");
    addLengthConstraint("b");
    addLengthConstraint("c");
    break;

  case PointGroup::LatticeSystem::Monoclinic:
    declareParameter("a", 1.0);
    declareParameter("b", 1.0);
    declareParameter("c", 1.0);
    addLengthConstraint("a");
    addLengthConstraint("b");
    addLengthConstraint("c");

    declareParameter("Beta", 90.0);
    addAngleConstraint("Beta");
    break;

  case PointGroup::LatticeSystem::Rhombohedral:
    declareParameter("a", 1.0);
    declareParameter("Alpha", 90.0);
    addLengthConstraint("a");
    addAngleConstraint("Alpha");
    break;

  default:
    // triclinic
    declareParameter("a", 1.0);
    declareParameter("b", 1.0);
    declareParameter("c", 1.0);
    addLengthConstraint("a");
    addLengthConstraint("b");
    addLengthConstraint("c");

    declareParameter("Alpha", 90.0);
    declareParameter("Beta", 90.0);
    declareParameter("Gamma", 90.0);
    addAngleConstraint("Alpha");
    addAngleConstraint("Beta");
    addAngleConstraint("Gamma");
    break;
  }

  declareParameter("ZeroShift", 0.0);
}

/// Adds a default constraint so that cell edge lengths can not be less than 0.
void PawleyParameterFunction::addLengthConstraint(const std::string &parameterName) {
  auto cellEdgeConstraint = std::make_unique<BoundaryConstraint>(this, parameterName, 0.0, true);
  cellEdgeConstraint->setPenaltyFactor(1e12);
  addConstraint(std::move(cellEdgeConstraint));
}

/// Adds a default constraint so cell angles are in the range 0 to 180.
void PawleyParameterFunction::addAngleConstraint(const std::string &parameterName) {
  auto cellAngleConstraint = std::make_unique<BoundaryConstraint>(this, parameterName, 0.0, 180.0, true);
  cellAngleConstraint->setPenaltyFactor(1e12);
  addConstraint(std::move(cellAngleConstraint));
}

/// Tries to extract and store the center parameter name from the function.
void PawleyParameterFunction::setCenterParameterNameFromFunction(const IPeakFunction_sptr &profileFunction) {
  m_profileFunctionCenterParameterName.clear();
  if (profileFunction) {
    m_profileFunctionCenterParameterName = profileFunction->getCentreParameterName();
  }
}

DECLARE_FUNCTION(PawleyFunction)

/// Constructor
PawleyFunction::PawleyFunction()
    : IPawleyFunction(), m_compositeFunction(), m_pawleyParameterFunction(), m_peakProfileComposite(), m_hkls(),
      m_dUnit(), m_wsUnit(), m_peakRadius(5) {
  auto peakRadius = Kernel::ConfigService::Instance().getValue<int>("curvefitting.peakRadius");
  m_peakRadius = peakRadius.get_value_or(5);
}

void PawleyFunction::setMatrixWorkspace(std::shared_ptr<const MatrixWorkspace> workspace, size_t wi, double startX,
                                        double endX) {
  if (workspace) {
    Axis *xAxis = workspace->getAxis(wi);
    Kernel::Unit_sptr wsUnit = xAxis->unit();

    if (std::dynamic_pointer_cast<Units::Empty>(wsUnit) || std::dynamic_pointer_cast<Units::dSpacing>(wsUnit)) {
      m_wsUnit = m_dUnit;
    } else {
      double factor, power;
      if (wsUnit->quickConversion(*m_dUnit, factor, power)) {
        m_wsUnit = wsUnit;
      } else {
        throw std::invalid_argument("Can not use quick conversion for unit.");
      }
    }
  }

  m_wrappedFunction->setMatrixWorkspace(workspace, wi, startX, endX);
}

/// Sets the crystal system on the internal parameter function and updates the
/// exposed parameters
void PawleyFunction::setLatticeSystem(const std::string &latticeSystem) {
  m_pawleyParameterFunction->setAttributeValue("LatticeSystem", latticeSystem);
  m_compositeFunction->checkFunction();
}

/// Sets the profile function and replaces already existing functions in the
/// internally stored CompositeFunction.
void PawleyFunction::setProfileFunction(const std::string &profileFunction) {
  m_pawleyParameterFunction->setAttributeValue("ProfileFunction", profileFunction);

  /* At this point PawleyParameterFunction guarantees that it's an IPeakFunction
   * and all existing profile functions are replaced.
   */
  for (size_t i = 0; i < m_peakProfileComposite->nFunctions(); ++i) {
    IPeakFunction_sptr oldFunction = std::dynamic_pointer_cast<IPeakFunction>(m_peakProfileComposite->getFunction(i));

    IPeakFunction_sptr newFunction = std::dynamic_pointer_cast<IPeakFunction>(
        FunctionFactory::Instance().createFunction(m_pawleyParameterFunction->getProfileFunctionName()));

    newFunction->setCentre(oldFunction->centre());
    try {
      newFunction->setFwhm(oldFunction->fwhm());
    } catch (...) {
      // do nothing.
    }
    newFunction->setHeight(oldFunction->height());

    m_peakProfileComposite->replaceFunction(i, newFunction);
  }

  // Update exposed parameters.
  m_compositeFunction->checkFunction();
}

/// Sets the unit cell from a string with either 6 or 3 space-separated numbers.
void PawleyFunction::setUnitCell(const std::string &unitCellString) {
  m_pawleyParameterFunction->setParametersFromUnitCell(strToUnitCell(unitCellString));
}

/// Transform d value to workspace unit
double PawleyFunction::getTransformedCenter(double d) const {
  if ((m_dUnit && m_wsUnit) && m_dUnit != m_wsUnit) {
    return UnitConversion::run(*m_dUnit, *m_wsUnit, d, 0, DeltaEMode::Elastic);
  }

  return d;
}

void PawleyFunction::setPeakPositions(const std::string &centreName, double zeroShift, const UnitCell &cell) const {
  for (size_t i = 0; i < m_hkls.size(); ++i) {
    double centre = getTransformedCenter(cell.d(m_hkls[i]));

    m_peakProfileComposite->getFunction(i)->setParameter(centreName, centre + zeroShift);
  }
}

size_t PawleyFunction::calculateFunctionValues(const API::IPeakFunction_sptr &peak, const API::FunctionDomain1D &domain,
                                               API::FunctionValues &localValues) const {
  size_t domainSize = domain.size();
  const double *domainBegin = domain.getPointerAt(0);
  const double *domainEnd = domain.getPointerAt(domainSize);

  double centre = peak->centre();
  double dx = m_peakRadius * peak->fwhm();

  auto lb = std::lower_bound(domainBegin, domainEnd, centre - dx);
  auto ub = std::upper_bound(lb, domainEnd, centre + dx);

  size_t n = std::distance(lb, ub);

  if (n == 0) {
    throw std::invalid_argument("Null-domain");
  }

  FunctionDomain1DView localDomain(lb, n);
  localValues.reset(localDomain);

  peak->functionLocal(localValues.getPointerToCalculated(0), localDomain.getPointerAt(0), n);

  return std::distance(domainBegin, lb);
}

/**
 * Calculates the function values on the supplied domain
 *
 * This function is the core of PawleyFunction. It calculates the d-value for
 * each stored HKL from the unit cell that is the result of the parameters
 * stored in the internal PawleyParameterFunction and adds the ZeroShift
 * parameter. The value is set as center parameter on the internally stored
 * PeakFunctions.
 *
 * @param domain :: Function domain.
 * @param values :: Function values.
 */
void PawleyFunction::function(const FunctionDomain &domain, FunctionValues &values) const {
  values.zeroCalculated();
  try {
    const auto &domain1D = dynamic_cast<const FunctionDomain1D &>(domain);

    UnitCell cell = m_pawleyParameterFunction->getUnitCellFromParameters();
    double zeroShift = m_pawleyParameterFunction->getParameter("ZeroShift");
    std::string centreName = m_pawleyParameterFunction->getProfileFunctionCenterParameterName();

    setPeakPositions(centreName, zeroShift, cell);

    FunctionValues localValues;

    for (size_t i = 0; i < m_peakProfileComposite->nFunctions(); ++i) {
      IPeakFunction_sptr peak = std::dynamic_pointer_cast<IPeakFunction>(m_peakProfileComposite->getFunction(i));

      try {
        size_t offset = calculateFunctionValues(peak, domain1D, localValues);
        values.addToCalculated(offset, localValues);
      } catch (const std::invalid_argument &) {
        // do nothing
      }
    }

    setPeakPositions(centreName, 0.0, cell);
  } catch (const std::bad_cast &) {
    // do nothing
  }
}

/// Removes all peaks from the function.
void PawleyFunction::clearPeaks() {
  m_peakProfileComposite =
      std::dynamic_pointer_cast<CompositeFunction>(FunctionFactory::Instance().createFunction("CompositeFunction"));
  m_compositeFunction->replaceFunction(1, m_peakProfileComposite);
  m_hkls.clear();
}

/// Clears peaks and adds a peak for each hkl, all with the same FWHM and
/// height.
void PawleyFunction::setPeaks(const std::vector<Kernel::V3D> &hkls, double fwhm, double height) {
  clearPeaks();

  for (const auto &hkl : hkls) {
    addPeak(hkl, fwhm, height);
  }
}

/// Adds a peak with the supplied FWHM and height.
void PawleyFunction::addPeak(const Kernel::V3D &hkl, double fwhm, double height) {
  m_hkls.emplace_back(hkl);

  IPeakFunction_sptr peak = std::dynamic_pointer_cast<IPeakFunction>(
      FunctionFactory::Instance().createFunction(m_pawleyParameterFunction->getProfileFunctionName()));

  peak->fix(peak->parameterIndex(m_pawleyParameterFunction->getProfileFunctionCenterParameterName()));

  try {
    peak->setFwhm(fwhm);
  } catch (...) {
    // do nothing.
  }

  peak->setHeight(height);

  m_peakProfileComposite->addFunction(peak);

  m_compositeFunction->checkFunction();
}

/// Returns the number of peaks that are stored in the function.
size_t PawleyFunction::getPeakCount() const { return m_hkls.size(); }

IPeakFunction_sptr PawleyFunction::getPeakFunction(size_t i) const {
  if (i >= m_hkls.size()) {
    throw std::out_of_range("Peak index out of range.");
  }

  return std::dynamic_pointer_cast<IPeakFunction>(m_peakProfileComposite->getFunction(i));
}

/// Return the HKL of the i-th peak.
Kernel::V3D PawleyFunction::getPeakHKL(size_t i) const {
  if (i >= m_hkls.size()) {
    throw std::out_of_range("Peak index out of range.");
  }

  return m_hkls[i];
}

/// Returns the internally stored PawleyParameterFunction.
PawleyParameterFunction_sptr PawleyFunction::getPawleyParameterFunction() const { return m_pawleyParameterFunction; }

void PawleyFunction::init() {
  setDecoratedFunction("CompositeFunction");

  if (!m_compositeFunction) {
    throw std::runtime_error("PawleyFunction could not construct internal CompositeFunction.");
  }

  m_dUnit = UnitFactory::Instance().create("dSpacing");
}

/// Checks that the decorated function has the correct structure.
void PawleyFunction::beforeDecoratedFunctionSet(const API::IFunction_sptr &fn) {
  CompositeFunction_sptr composite = std::dynamic_pointer_cast<CompositeFunction>(fn);

  if (!composite) {
    throw std::invalid_argument("PawleyFunction only works with "
                                "CompositeFunction. Selecting another "
                                "decorated function is not possible.");
  }

  m_compositeFunction = composite;

  if (m_compositeFunction->nFunctions() == 0) {
    m_peakProfileComposite =
        std::dynamic_pointer_cast<CompositeFunction>(FunctionFactory::Instance().createFunction("CompositeFunction"));

    m_pawleyParameterFunction = std::dynamic_pointer_cast<PawleyParameterFunction>(
        FunctionFactory::Instance().createFunction("PawleyParameterFunction"));

    m_compositeFunction->addFunction(m_pawleyParameterFunction);
    m_compositeFunction->addFunction(m_peakProfileComposite);
  } else {
    m_pawleyParameterFunction = std::dynamic_pointer_cast<PawleyParameterFunction>(m_compositeFunction->getFunction(0));
    m_peakProfileComposite = std::dynamic_pointer_cast<CompositeFunction>(m_compositeFunction->getFunction(1));
  }
}

} // namespace Mantid::CurveFitting::Functions