    /*****************************************************************************
     * Project: RooFit                                                           *
     * Package: RooFitModels                                                     *
     *    File: $Id: RooLandau.cc,v 1.7 2005/06/16 09:37:28 wverkerke Exp $
     * Authors:                                                                  *
     *   WV, Wouter Verkerke, UC Santa Barbara, verkerke@slac.stanford.edu       *
     *   DK, David Kirkby,    UC Irvine,         dkirkby@uci.edu                 *
     *                                                                           *
     * Copyright (c) 2000-2005, Regents of the University of California          *
     *                          and Stanford University. All rights reserved.    *
     *                                                                           *
     * Redistribution and use in source and binary forms,                        *
     * with or without modification, are permitted according to the terms        *
     * listed in LICENSE (http://roofit.sourceforge.net/license.txt)             *
     *****************************************************************************/
    // -- CLASS DESCRIPTION [PDF] --
    // Landau Distribution PDF...

    #include "RooFit.h"

    #include "RooLandau.h"
    #include "RooLandau.h"
    #include "RooRandom.h"

    ClassImp(RooLandau)

     RooLandau::RooLandau(const char *name, const char *title, RooAbsReal& _x, RooAbsReal& _mean, RooAbsReal& _sigma) :
      RooAbsPdf(name,title),
      x("x","Dependent",this,_x),
      mean("mean","Mean",this,_mean),
      sigma("sigma","Width",this,_sigma)
    {
    }

     RooLandau::RooLandau(const RooLandau& other, const char* name) :
      RooAbsPdf(other,name),
      x("x",this,other.x),
      mean("mean",this,other.mean),
      sigma("sigma",this,other.sigma)
    {
    }

     Double_t RooLandau::evaluate() const
    {
      return TMath::Landau(x, mean, sigma);
    }

     Int_t RooLandau::getGenerator(const RooArgSet& directVars, RooArgSet &generateVars, Bool_t /*staticInitOK*/) const
    {
      if (matchArgs(directVars,generateVars,x)) return 1 ;
      return 0 ;
    }

     void RooLandau::generateEvent(Int_t code)
    {
      assert(code==1) ;
      Double_t xgen ;
      while(1) {
        xgen = RooRandom::randomGenerator()->Landau(mean,sigma);
        if (xgen<x.max() && xgen>x.min()) {
          x = xgen ;
          break;
        }
      }
      return;
    }