GaussianMultipletSpectralElement.h

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//# SpectralElement.h: Describes (a set of related) spectral lines
//# Copyright (C) 2001,2003,2004
//# Associated Universities, Inc. Washington DC, USA.
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//# $Id: SpectralElement.h 20652 2009-07-06 05:04:32Z Malte.Marquarding $

#ifndef COMPONENTS_GAUSSIANMULTIPLETSPECTRALELEMENT_H
#define COMPONENTS_GAUSSIANMULTIPLETSPECTRALELEMENT_H

#include <casa/Arrays/Matrix.h>
#include <components/SpectralComponents/CompiledSpectralElement.h>
#include <components/SpectralComponents/GaussianSpectralElement.h>

namespace casa { //# NAMESPACE CASA - BEGIN

// <summary>
// Describes a multiplet of Gaussian shaped spectral lines
// </summary>

// <use visibility=export>

// <reviewed reviewer="" date="yyyy/mm/dd" tests="tSpectralFit" demos="">
// </reviewed>

// <prerequisite>
//   <li> <linkto module=SpectralElement>SpectralElement</linkto> module
//   <li> <linkto module=GaussianSpectralElement>CompiledSpectralElement</linkto> module
//   <li> <linkto module=CompiledSpectralElement>CompiledSpectralElement</linkto> module
// </prerequisite>
//
// <etymology>
// From Gaussian and multiplet and spectral line and element
// </etymology>
//
// <synopsis>
// The GaussianMultipletSpectralElement class describes a multiplet
// of Gaussian shaped spectral lines for describing spectral profile.
//
// Relationships between Gaussians in the multiplet must be specified.
// Any combination of one or more of fixed relationships between line
// center offsets, line amplitude ratios, and/or line width ratios can
// be specified between a single reference line in the multiplet and
// other (non-reference) lines in the multiplet. The constructor
// takes a Vector of GaussianSpectralElements which describes the estimates
// of the n Gaussians in the multiplet. These objects themselves are not
// used in the fitting, but are used only to create the function that describes
// the multiplet. The first element in this Vector represents the reference line
// to which parameters of the other lines are constrained. In addition, the
// constructor takes an n-1 x 3 Matrix<Double> describing the fixed relationships
// between the reference line and the other lines in the multiplet. Each ith row
// describes the fixed relationship(s) between the (i+1)th and the zeroth
// (reference) Gaussian. The first element of each row describes the ratio of
// amplitudes between the (i+1)th and reference Gaussian, the second element
// describes the difference between the center locations of the (i+1)th and
// reference Gaussian, and the third represents the ratio of the FWHM of the
// (i+1)th and reference Gaussian. A value of 0 for any of these indicates there
// is no fixed relationship for that parameter. At least one value must be non-zero
// for each row and any combination of elements (including all of them) can be
// non-zero for any row in this matrix. The values of parameters of non-reference
// lines in the input vector that are constrained to the reference line are
// implicitly ignored and set in the constructor according to the specified
// constraint. If any of the parameters of the reference line are specified as
// fixed, the corresponding parameters of any non-reference lines which have the
// corresponding parameters constrained to the reference line are also implicitly
// fixed. Fixing a parameter in a non-reference line that is constrained to the
// corresponding parameter of the reference line that is not fixed will cause an
// exception.
// </synopsis>
//
// <example>
// This is how to specify a doublet in which the only constraint is that the amplitudes
// between the lines must be fixed, the first Gaussian must have an ampliute of 0.6 times
// the zeroth (reference) Gaussian. Other than that, all other parameters can
// vary during the fit:

// GaussianSpectralElement reference(5, 25, 16);
// // The amplitude value of first is ignored because of the relationship to the
// // reference, but it still must be specified in the constructor and must be
// // non-zero or an exception will be thrown.
// GaussianSpectralElement first(1, 40, 17);
// Vector<GaussianSpectralElement> pair(2);
// pair[0] = reference;
// pair[1] = first;
// // initialize constraints matrix to have nothing constrained (all values 0)
// Matrix<Double> fixedRel(1, 3, 0);
// // Set the ratio of amplitudes between the first and reference (zeroth) line
// // to be 0.6.
// fixedRel[0][0] = 0.6
// GaussianMultipletSpectralElement doublet(pair,"",fixedRel);
// </example>
//
// <motivation>
// To allow specifying constraints between different Gaussian spectral
// lines for fitting, eg to support fitting of doublets.
// </motivation>

class GaussianMultipletSpectralElement: public CompiledSpectralElement {
public:

        // Construct a Gaussian multiplet. The values of non-reference (non-zeroth)
        // estimates will be automatically adjusted if there is a fixed relationship
        // between a non-reference Gaussian parameter and the corresponding reference
        // Gaussian parameter.
        GaussianMultipletSpectralElement(
                const Vector<GaussianSpectralElement>& estimates,
                const Matrix<Double>& fixedRelationships
        );

        // copy semantics
        GaussianMultipletSpectralElement(
                const GaussianMultipletSpectralElement& other
        );

        ~GaussianMultipletSpectralElement();

        SpectralElement* clone() const;

        // copy semantics
        GaussianMultipletSpectralElement &operator=(
                const GaussianMultipletSpectralElement& other
        );

        Bool operator==(
                const GaussianMultipletSpectralElement& other
        ) const;

        // get the gaussians
        const Vector<GaussianSpectralElement>& getGaussians() const;

        // get the constraints matrix
        const Matrix<Double>& getConstraints() const;

        //<group>
        // These methods must be public because the architecture of
        // the class hierarchy requires it and set() and setError()
        // must be accessible by fitters. However, it is strongly
        // recommended that other classes not call these methods for
        // object configuration but rather set them implicitly at
        // construction via the Vector<GaussianSpectralElement>
        // passed to the constructor.
        void set(const Vector<Double>& param);

        void setError(const Vector<Double> &err);

        void fix(const Vector<Bool>& fix);
        // </group>
        // Save to a record.
        Bool toRecord(RecordInterface& out) const;

private:
        Vector<GaussianSpectralElement> _gaussians;
        Matrix<Double> _constraints;
        Matrix<uInt> _paramIndices;
};

ostream &operator<<(ostream &os, const GaussianMultipletSpectralElement &elem);

} //# NAMESPACE CASA - END

#endif