source: trunk/external-alma/components/SpectralComponents/SpectralFit2.tcc@ 3021

//# SpectralFit2.cc: Least Squares fitting of spectral elements: templated part
//# Copyright (C) 2001,2002,2004
//# Associated Universities, Inc. Washington DC, USA.
//#
//# This library is free software; you can redistribute it and/or modify it
//# under the terms of the GNU Library General Public License as published by
//# the Free Software Foundation; either version 2 of the License, or (at your
//# option) any later version.
//#
//# This library is distributed in the hope that it will be useful, but WITHOUT
//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
//# License for more details.
//#
//# You should have received a copy of the GNU Library General Public License
//# along with this library; if not, write to the Free Software Foundation,
//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
//#
//# Correspondence concerning AIPS++ should be addressed as follows:
//#        Internet email: aips2-request@nrao.edu.
//#        Postal address: AIPS++ Project Office
//#                        National Radio Astronomy Observatory
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//#
//# $Id: SpectralFit2.tcc 21465 2014-06-19 05:56:56Z gervandiepen $

//# Includes
#include <components/SpectralComponents/SpectralFit.h>

#include <casa/Utilities/PtrHolder.h>
#include <components/SpectralComponents/CompiledSpectralElement.h>
#include <components/SpectralComponents/GaussianSpectralElement.h>
#include <components/SpectralComponents/LogTransformedPolynomialSpectralElement.h>
#include <components/SpectralComponents/LorentzianSpectralElement.h>
#include <components/SpectralComponents/PolynomialSpectralElement.h>
#include <components/SpectralComponents/PowerLogPolynomialSpectralElement.h>
#include <scimath/Fitting/NonLinearFitLM.h>
#include <scimath/Functionals/CompiledFunction.h>
#include <scimath/Functionals/CompoundFunction.h>
#include <scimath/Functionals/CompoundParam.h>
#include <scimath/Functionals/Gaussian1D.h>
#include <scimath/Functionals/Lorentzian1D.h>
#include <scimath/Functionals/Polynomial.h>
#include <scimath/Functionals/PowerLogarithmicPolynomial.h>

namespace casa { //# NAMESPACE CASA - BEGIN

//# Templated member functions

template <class MT>
Bool SpectralFit::fit(const Vector<MT> &y,
                      const Vector<MT> &x,
                      const Vector<Bool> *mask) {
  Vector<MT> sigma(x.nelements());
  sigma = 1.0;
  return fit(sigma, y, x, mask);
}

template <class MT>
Bool SpectralFit::fit(
        const Vector<MT> &sigma, const Vector<MT> &y,
        const Vector<MT> &x, const Vector<Bool> *mask
) {
        NonLinearFitLM<MT> fitter;
        iter_p = 0;
        // The functions to fit
        CompoundFunction<AutoDiff<MT> > func;
        uInt ncomps = slist_p.nelements();
        PtrHolder<Function<AutoDiff<MT> > > autodiff;
        for (uInt i=0; i<ncomps; i++) {
                SpectralElement *elem = slist_p[i];
                uInt nparms = elem->getOrder();
                SpectralElement::Types type = slist_p[i]->getType();
                switch(type) {
                case SpectralElement::GAUSSIAN: {
                        autodiff.set(new Gaussian1D<AutoDiff<MT> >());
                }
                break;
                case SpectralElement::POLYNOMIAL: {
                        PolynomialSpectralElement *x = dynamic_cast<PolynomialSpectralElement *>(elem);
                        autodiff.set(new Polynomial<AutoDiff<MT> >(x->getDegree()));
                }
                break;
                case SpectralElement::COMPILED:
                        // Allow fall through; these use the same code
                case SpectralElement::GMULTIPLET: {
                        CompiledSpectralElement *x = dynamic_cast<CompiledSpectralElement *>(elem);
                        autodiff.set(new CompiledFunction<AutoDiff<MT> >());
                        dynamic_cast<CompiledFunction<AutoDiff<MT> > *>(
                                autodiff.ptr()
                        )->setFunction(x->getFunction());
                }
                break;
                case SpectralElement::LORENTZIAN: {
                        autodiff.set(new Lorentzian1D<AutoDiff<MT> >());
                }
                break;
                case SpectralElement::POWERLOGPOLY: {
                        Vector<Double> parms = elem->get();
                        autodiff.set(new PowerLogarithmicPolynomial<AutoDiff<MT> > (nparms));
                }
                break;
                case SpectralElement::LOGTRANSPOLY: {
                        LogTransformedPolynomialSpectralElement *x = dynamic_cast<
                                LogTransformedPolynomialSpectralElement*
                        >(elem);
                        // treated as a polynomial for fitting purposes. The caller is responsible for passing the ln's of
                        // the ordinate and obscissa values to the fitter.
                        autodiff.set(new Polynomial<AutoDiff<MT> > (x->getDegree()));
                }
                break;
                default:
                        throw AipsError("SpectralFit::fit(): Logic Error: Unhandled SpectralElement type");
                }
                Vector<Double> parms = elem->get();
                Vector<Bool> fixed = elem->fixed();
                for (uInt j=0; j<nparms; j++) {
                        (*autodiff)[j] = AutoDiff<MT>(parms[j], nparms, j);
                        if (j == PCFSpectralElement::WIDTH && type == SpectralElement::GAUSSIAN) {
                                (*autodiff)[j] *= GaussianSpectralElement::SigmaToFWHM;
                        }
                        autodiff->mask(j) = ! fixed[j];
                }
                func.addFunction(*autodiff);
        }
        fitter.setFunction(func);
        // Max. number of iterations
        fitter.setMaxIter(50+ ncomps*10);
        // Convergence criterium
        fitter.setCriteria(0.001);
        // Fit
        Vector<MT> sol;
        Vector<MT> err;
        sol = fitter.fit(x, y, sigma, mask);
        err = fitter.errors();
        // Number of iterations
        iter_p = fitter.currentIteration();
        chiSq_p = fitter.getChi2();
        uInt j = 0;
        Vector<Double> tmp, terr;
        for (uInt i=0; i<ncomps; i++) {
                SpectralElement *element = slist_p[i];
                uInt nparms = element->getOrder();
                tmp.resize(nparms);
                terr.resize(nparms);
                SpectralElement::Types type = element->getType();
                for (uInt k=0; k<nparms; k++) {
                        Bool convertGaussWidth = k==PCFSpectralElement::WIDTH && type == SpectralElement::GAUSSIAN;
                        tmp(k) = convertGaussWidth
                                ? sol(j) / GaussianSpectralElement::SigmaToFWHM
                                : sol(j);
                        terr(k) = convertGaussWidth
                                ? err(j) / GaussianSpectralElement::SigmaToFWHM
                                : err(j);
                        j++;
                };
                element->set(tmp);
                element->setError(terr);
        }
        return fitter.converged();
}


} //# NAMESPACE CASA - END