//
//   The fitting function fcn calculates the chisquare value based on all parameters
//   
//   More details on the various functions or parameters for these functions
//   can be obtained in an interactive ROOT session with:
//    Root > TMinuit *minuit = new TMinuit(10);
//    Root > minuit->mnhelp("*")  to see the list of possible keywords
//    Root > minuit->mnhelp("SET") explains most parameters
//

#include "TMinuit.h"
TH1F *testHist;
CgamFit *SeGAfits = new CgamFit(8, 80);

//______________________________________________________________________________
void fcn(Int_t &npar, Double_t *gin, Double_t &f, Double_t *par, Int_t iflag)
{

  Double_t delta, chisq = 0;
  delta = 1+par[0]+3*par[0]*par[0];
  chisq+=delta*delta;
  delta = 5+7*par[1]+11*par[1]*par[1]*par[1];
  chisq+=delta*delta;
  delta = 5+7*par[2]+21*par[2]*par[2];
  chisq+=delta*delta;
  //  testHist->Fit("linFit","+","",0,5);
  cout << "************" << SeGAfits->FitLine(testHist,1490) << endl;;
  

  f = chisq;
}

void exFitInFit()
{

  char file_name[80];
  /*
  Double_t y[5] = {1.1,2.08,2.97,4.06,5.19};
  testHist = new TH1F("test","test",5,0,5);

  for(Int_t i = 0; i < 5; i ++) {
    testHist->SetBinContent(i+1,y[i]);
  }

  TF1 *linFit = new TF1("linFit","[0]+[1]*x");
  testHist->Draw();
  testHist->Fit("linFit","+","",0,5);
  */

  sprintf(file_name,"test.root");
  TFile f = file_name;
  testHist = (TH1F*)gDirectory->Get("sega_e_calDop22_1");
  testHist->Draw();
  cout << "************" << SeGAfits->FitLine(testHist,1490) << endl;;

  TMinuit *gMinuit = new TMinuit(3);

  gMinuit->SetFCN(fcn);

  Double_t arglist[10];
  Int_t ierflg = 0;
  
  arglist[0] = 1;
  gMinuit->mnexcm("SET ERR", arglist ,1,ierflg);

  gMinuit->mnexcm("SET ERR", arglist ,1,ierflg);  
  //___________________________________________________________________________
  // Set starting values and step sizes for parameters

  gMinuit->mnparm(0, "par01", 1.5, 0.01, -50, 50,ierflg);
  gMinuit->mnparm(1, "par02", 5, 0.01, -50, 50,ierflg);
  gMinuit->mnparm(2, "par03", 12, 0.01, -50, 50,ierflg);
  
  //___________________________________________________________________________
  // Now ready for minimization step

  arglist[0] = 3000;
  arglist[1] = 1.;
  gMinuit->mnexcm("MIGRAD", arglist ,2,ierflg);

  //___________________________________________________________________________
  // Print results

  Double_t amin,edm,errdef;
  Int_t nvpar,nparx,icstat;
  gMinuit->mnstat(amin,edm,errdef,nvpar,nparx,icstat);
  gMinuit->mnprin(3,amin);

}