/**
*    Copyright (C)  DataMelt project. The jHPLot package by S.Chekanov and Work.ORG
*    All rights reserved.
*
*    This program is free software; you can redistribute it and/or modify it under the terms
*    of the GNU General Public License as published by the Free Software Foundation; either
*    version 3 of the License, or any later version.
*
*    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
*    without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*    See the GNU General Public License for more details.
*
*    You should have received a copy of the GNU General Public License along with this program;
*    if not, see .
*
*    Additional permission under GNU GPL version 3 section 7:
*    If you have received this program as a library with written permission from the DataMelt team,
*    you can link or combine this library with your non-GPL project to convey the resulting work.
*    In this case, this library should be considered as released under the terms of
*    GNU Lesser public license (see ),
*    provided you include this license notice and a URL through which recipients can access the
*    Corresponding Source.
**/

package jhplot.fit;

import hep.aida.ref.function.AbstractIFunction;
import java.lang.Math;


/**
  * Build a Breit-Wigner distribution.
  * 
  * @author S.Chekanov
  *
**/


public class BreitWigner extends AbstractIFunction {
    
    public BreitWigner() {
        this("BreitWigner");
    }
    
    public BreitWigner(String title) {
        super(title, 1, 3);
    }
    
    public BreitWigner(String[] variableNames, String[] parameterNames) {
        super(variableNames, parameterNames);
    }
    
    public double value(double[] v) {

            double  bw = p[2] /((v[0]-p[1])*(v[0]-p[1]) + p[2]*p[2]/4);
            return p[0]*bw/(2*Math.PI);

    }
    
    // Here change the parameter names
    protected void init(String title) {
 
           parameterNames[0] = "norm";
            parameterNames[1] = "mean";
              parameterNames[2] = "gamma";
//       for (int i=0; i