/** Calculate Chi^2 of the a function with all parameters are fixed
*/
double RefinePowderInstrumentParameters2::calculateFunctionError(IFunction_sptr function,
Workspace2D_sptr dataws, int wsindex)
{
// 1. Record the fitting information
vector<string> parnames = function->getParameterNames();
vector<bool> vecFix(parnames.size(), false);
for (size_t i = 0; i < parnames.size(); ++i)
{
bool fixed = function->isFixed(i);
vecFix[i] = fixed;
if (!fixed)
function->fix(i);
}
// 2. Fit with zero iteration
double chi2;
string fitstatus;
doFitFunction(function, dataws, wsindex, "Levenberg-MarquardtMD", 0, chi2, fitstatus);
// 3. Restore the fit/fix setup
for (size_t i = 0; i < parnames.size(); ++i)
{
if (!vecFix[i])
function->unfix(i);
}
return chi2;
}
/** Set parameter fitting setup (boundary, fix or unfix) to function from Parameter map
*/
void RefinePowderInstrumentParameters2::setFunctionParameterFitSetups(IFunction_sptr function,
map<string, Parameter> params)
{
// 1. Prepare
vector<string> funparamnames = m_positionFunc->getParameterNames();
// 2. Set up
std::map<std::string, Parameter>::iterator paramiter;
for (size_t i = 0; i < funparamnames.size(); ++i)
{
string parname = funparamnames[i];
paramiter = params.find(parname);
if (paramiter != params.end())
{
// Found, set up the parameter
Parameter& param = paramiter->second;
if (param.fit)
{
// If fit. Unfix it and set up constraint
function->unfix(i);
double lowerbound = param.minvalue;
double upperbound = param.maxvalue;
if (lowerbound >= -DBL_MAX*0.1 || upperbound <= DBL_MAX*0.1)
{
// If there is a boundary
BoundaryConstraint *bc = new BoundaryConstraint(function.get(), parname, lowerbound,
upperbound, false);
function->addConstraint(bc);
}
}
else
{
// If fix.
function->fix(i);
}
}
else
{
// Not found and thus quit
stringstream errss;
errss << "Peak profile parameter " << parname << " is not found in input parameters. ";
g_log.error(errss.str());
throw runtime_error(errss.str());
}
} // ENDFOR parameter name
g_log.notice() << "Fit function:\n" << function->asString() << "\n";
return;
}