/***************************************************************************** 
 * Project: RooFit                                                           * 
 *                                                                           * 
 * This code was autogenerated by RooClassFactory                            * 
 *****************************************************************************/ 

// Your description goes here... 

#include "Riostream.h" 

#include "Roo2DimGaussVar.h" 
#include "RooAbsReal.h" 
#include "RooAbsCategory.h" 
#include <math.h> 
#include "TMath.h" 

ClassImp(Roo2DimGaussVar);

Roo2DimGaussVar::Roo2DimGaussVar(const char *name, const char *title, 
		RooAbsReal& _x,
		RooAbsReal& _y,
		RooAbsReal& _rho,
		RooAbsReal& _sigX,
		RooAbsReal& _sigY,
		RooAbsReal& _muX,
		RooAbsReal& _muY,
		RooAbsReal& _height) :
				RooAbsReal(name,title),
				x("x","x",this,_x),
				y("y","y",this,_y),
				rho("rho","rho",this,_rho),
				sigX("sigX","sigX",this,_sigX),
				sigY("sigY","sigY",this,_sigY),
				muX("muX","muX",this,_muX),
				muY("muY","muY",this,_muY),
				height("height","height",this,_height)
{ 
	;
} 


Roo2DimGaussVar::Roo2DimGaussVar(const Roo2DimGaussVar& other, const char* name) :  
				RooAbsReal(other,name),
				x("x",this,other.x),
				y("y",this,other.y),
				rho("rho",this,other.rho),
				sigX("sigX",this,other.sigX),
				sigY("sigY",this,other.sigY),
				muX("muX",this,other.muX),
				muY("muY",this,other.muY),
				height("height",this,other.height)
{ 
} 


Double_t Roo2DimGaussVar::evaluate() const 
{ 
	double factor=2*TMath::Pi()*sigX.arg().getVal()*sigY.arg().getVal();
	factor*=TMath::Sqrt(1-rho.arg().getVal()*rho.arg().getVal());
	factor=1./factor;
	double val1=(x-muX.arg().getVal())*(x-muX.arg().getVal());
	val1/=sigX.arg().getVal()*sigX.arg().getVal();;
	double val2=(y-muY.arg().getVal())*(y-muY.arg().getVal());
	val2/=sigY.arg().getVal()*sigY.arg().getVal();
	double val3=2*rho.arg().getVal()*(x-muX.arg().getVal())*(y-muY.arg().getVal());
	val3/=sigX.arg().getVal()*sigY.arg().getVal();

	double exponent=-1./(2*(1-rho.arg().getVal()*rho.arg().getVal()));
	exponent*=(val1+val2-val3);

	double retval=height.arg().getVal()*TMath::Exp(exponent);

	return retval;
}