/*
 * CauchyDistribution.hh
 *
 * Class to provide calculation of the value and the derivatives of
 * the Cauchy (Breit-Wigner) distribution for fitting with the Minuit2
 * CombinedMinimizer class.
 *
 *  Created on: Oct 13, 2015
 *      Author: Hovanes Egiyan
 */

#ifndef CAUCHYDISTRIBUTION_HH_
#define CAUCHYDISTRIBUTION_HH_

#include <math.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <stdint.h>

#include <iostream>
#include <string>
#include <map>
#include <vector>
#include <sstream>
#include <exception>
#include <stdexcept>
#include <numeric>

#include <Minuit2/FCNGradientBase.h>
#include <Minuit2/FCNGradientBase.h>

class CauchyDistribution: public ROOT::Minuit2::FCNGradientBase {
protected:
	const static unsigned cdNumberOfParameters;
	double cdErrorDef;
	const std::vector<double>* cdAxisX;
	const std::vector<double>* cdAxisY;

public:
	CauchyDistribution( const std::vector<double>* xAxis, const std::vector<double>* yAxis );
	virtual ~CauchyDistribution();
	virtual double operator()( const std::vector<double>& x ) const;
	CauchyDistribution& operator=( const CauchyDistribution& dist );

	inline virtual double Up() const {
		return cdErrorDef;
	}

	inline virtual void SetErrDef( double errDef ) {
		setErrorDef( errDef );
	}

	// Method to calculate the gradient of the function to minimize wrt parameters.
	virtual std::vector<double> Gradient( const std::vector<double>& x ) const;

	// Turns off checking the gradient calculations against the calculation by Minuit.
	virtual bool CheckGradient() const {
		// Check will not be performed
		return false;
	}

	inline virtual const std::vector<double>* getAxisX() const {
		return cdAxisX;
	}

	inline virtual const std::vector<double>* setAxisX( const std::vector<double>* cdAxisX ) {
		return (this->cdAxisX = cdAxisX);
	}

	inline virtual const std::vector<double>* getAxisY() const {
		return cdAxisY;
	}

	inline virtual const std::vector<double>* setAxisY( const std::vector<double>* cdAxisY ) {
		return (this->cdAxisY = cdAxisY);
	}

	inline double getErrorDef() const {
		return cdErrorDef;
	}

	inline void setErrorDef( double errDef ) {
		cdErrorDef = errDef;
	}

	inline static unsigned getNumberOfParameters() {
		return cdNumberOfParameters;
	}

//	inline static void setNumberOfParameters( const unsigned numberOfParameters ) {
//		cdNumberOfParameters = numberOfParameters;
//	}
};

#endif /* CAUCHYDISTRIBUTION_HH_ */