/** 
* @file PDFDirichlet.cpp
* @brief Normal Distribution / Gaussian PDF
* @author Erik Rodner
* @date 01/29/2008

*/
#include <iostream>

#include "vislearning/math/pdf/PDFDirichlet.h"
#include "vislearning/math/pdf/gslRandomNumberGenerator.h"

using namespace OBJREC;

using namespace std;
// refactor-nice.pl: check this substitution
// old: using namespace ice;
using namespace NICE;



PDFDirichlet::PDFDirichlet( double _alpha, int dimension ) : alpha(dimension)
{
    for ( int i = 0 ; i < dimension ; i++ )
	alpha[i] = _alpha / dimension;
}

// refactor-nice.pl: check this substitution
// old: PDFDirichlet::PDFDirichlet ( const Vector & _alpha ) : alpha(_alpha)
PDFDirichlet::PDFDirichlet ( const NICE::Vector & _alpha ) : alpha(_alpha)
{
}

PDFDirichlet::~PDFDirichlet()
{
}

// refactor-nice.pl: check this substitution
// old: double PDFDirichlet::getNLogDensity ( const Vector & x ) const
double PDFDirichlet::getNLogDensity ( const NICE::Vector & x ) const
{
#ifdef NICE_USELIB_GSL
    return gsl_ran_dirichlet_lnpdf ( alpha.size(), alpha.getDataPointerConst(), x.getDataPointerConst() );
#else
    #warning "PDFDirichlet::getNLogDensity: this function needs the GNU Scientific Library"
    fprintf (stderr, "PDFDirichlet::getNLogDensity: this function needs the GNU Scientific Library\n");
    exit(-1);
    return 0.0;
#endif
}

// refactor-nice.pl: check this substitution
// old: double PDFDirichlet::getProb ( const Vector & x ) const
double PDFDirichlet::getProb ( const NICE::Vector & x ) const
{
#ifdef NICE_USELIB_GSL
    return gsl_ran_dirichlet_pdf ( alpha.size(), alpha.getDataPointerConst(), x.getDataPointerConst() );
#else
    #warning "PDFDirichlet::getProb: this function needs the GNU Scientific Library"
    fprintf (stderr, "PDFDirichlet::getProb: this function needs the GNU Scientific Library\n");
    exit(-1);
    return 0.0;
#endif

}

int PDFDirichlet::getDimension () const
{
    return alpha.size();
}

void PDFDirichlet::sample ( VVector & samples, int count ) const
{
#ifdef NICE_USELIB_GSL
    initGSLRandom();

    for ( int i = 0 ; i < count ; i++ )
    {
	// refactor-nice.pl: check this substitution
	// old: Vector x ( alpha.size() );
	NICE::Vector x ( alpha.size() );
	gsl_ran_dirichlet (randomGSL, alpha.size(), alpha.getDataPointerConst(), x.getDataPointer() );
	samples.push_back ( x );
    }
#else
    #warning "PDFDirichlet::sample: this function needs the GNU Scientific Library"
    fprintf (stderr, "PDFDirichlet::sample: this function needs the GNU Scientific Library\n");
    exit(-1);
#endif

}