BCGaussianPrior.h

#ifndef __BCGAUSSIANPRIOR__H
#define __BCGAUSSIANPRIOR__H

/*
 * Copyright (C) 2007-2018, the BAT core developer team
 * All rights reserved.
 *
 * For the licensing terms see doc/COPYING.
 * For documentation see http://mpp.mpg.de/bat
 */

// ---------------------------------------------------------

#include "BCPrior.h"

#include <limits>
#include <cmath>

class TF1;

// ---------------------------------------------------------

class BCGaussianPrior : public BCPrior
{
public:
    BCGaussianPrior(double mean, double sigma);

    virtual ~BCGaussianPrior() {};

    virtual BCPrior* Clone() const
    { return new BCGaussianPrior(*this); }

    virtual bool IsValid() const
    { return std::isfinite(fMean) and std::isfinite(fSigma) and fSigma > 0;}

    virtual double GetLogPrior(double x)
    { return -0.5 * (x - fMean) * (x - fMean) / fSigma / fSigma - log(fSigma) - 0.5 * log(2 * M_PI); }

    virtual double GetMode(double xmin = -std::numeric_limits<double>::infinity(), double xmax = std::numeric_limits<double>::infinity())
    { if (fMean < xmin) return xmin; if (fMean > xmax) return xmax; return fMean; }

    virtual double GetRawMoment(unsigned n, double xmin = -std::numeric_limits<double>::infinity(), double xmax = std::numeric_limits<double>::infinity());

    virtual double GetIntegral(double xmin = -std::numeric_limits<double>::infinity(), double xmax = std::numeric_limits<double>::infinity());

    void SetMean(double mean)
    { fMean = mean; }

    void SetSigma(double sigma)
    { fSigma = sigma; }

    void SetParameters(double mean, double sigma)
    { SetMean(mean); SetSigma(sigma); }

protected:
    double fMean;                                   
    double fSigma;                              
};

#endif