#include "RooAbsReal.h"
#include "RooGaussian.h"
#include "RooMinuit.h"
#include "RooRealVar.h"
#include "RooWorkspace.h"

RooWorkspace *GetWorkspace()
{
  RooWorkspace *ws = new RooWorkspace("ws");
  RooRealVar x("x","x",-5,5);
  RooRealVar m("m","m",0,-2,2);
  RooRealVar s("s","s",1,0,3);
  RooGaussian g("g","g",x,m,s);
  ws->import(g);
  return ws;
}

int testTVF()
{
  RooWorkspace *ws = GetWorkspace();
  RooDataSet *data = (RooDataSet*)ws->pdf("g")->generate(RooArgSet(*ws->var("x")),10000);
  ws->pdf("g")->fitTo(*data);

  RooAbsReal* nll = ws->pdf("g")->createNLL(*data) ;
  //double nll0= nll->getVal(nll->getVariables());
//    RooFormulaVar nll2("nll2",("@0-"+std::to_string(nll0)).c_str(),*nll) ;
  RooMinuit m(*nll) ;
  m.migrad() ;
  m.hesse() ;
  m.save();

  return 0;
}