#include "Riostream.h"
#include "TFile.h"
#include "TH1.h"
#include "TNtuple.h"
#include "TF1.h"
#include "TSpectrum.h"
void fithisto() 
{
Int_t i, npeaks = 5;

  TGraph *g = new TGraph("eu_gu_1.txt");
  // g->Sort(); // just a precaution
  Int_t n = g->GetN();//get the no. of points on the TGraph *g
  Double_t source[n];
  Double_t *x = new Double_t[(n + 1)];
  x[0] = (3.0 * g->GetX()[0] - g->GetX()[1]) / 2.0;
  x[n] = (3.0 * g->GetX()[(n - 1)] - g->GetX()[(n - 2)]) / 2.0;
  for (Int_t i = 1; i < n; i++)
    { x[i] = (g->GetX()[(i - 1)] + g->GetX()[i]) / 2.0; }
  TH1D *h = new TH1D("h", "spectrum;x-value(Channels);#counts", n, x);
 
  h->FillN(n, g->GetX(), g->GetY());
  h->Sumw2(kFALSE); // restore proper errors
  delete [] x; // no longer needed
  delete g; // no longer needed
  TF1 *f1 = new TF1("f1", "gausn(0) + pol1(3)", 400., 435.); // linear background
  f1->SetParameters(2800., 415., 2., 0., 0.);
  h->Fit("f1", "LBR+");
  TF1 *f2 = new TF1("f2", "gausn(0) + pol1(3)", 830., 846.); // linear background
  f2->SetParameters(1000., 838., 2., 0., 0.);
  h->Fit("f2", "LBR+");
  TF1 *f3 = new TF1("f3", "gausn(0) + pol1(3)", 1160., 1200.);
  f3->SetParameters(2700., 1178., 2., 0., 0.);
  h->Fit("f3", "LBR+");
  TF1 *f4 = new TF1("f4", "gausn(0) + pol1(3)", 1512., 1526.); // clean peak, no background
  f4->SetParameters(280., 1519., 3., 0., 0.);
  h->Fit("f4", "LBR+");
  TF1 *f5 = new TF1("f5", "gausn(0) + pol1(3)", 2654., 2674.); // clean peak, no background
  f5->SetParameters(580., 2664., 3., 0., 0.);
  h->Fit("f5", "LBR+");
  TF1 *f6 = new TF1("f6", "gausn(0) + pol1(3)", 2954., 2978.); // clean peak, no background
  f6->SetParameters(200., 2966., 3., 0., 0.);
  h->Fit("f6", "LBR+");
  TF1 *f7 = new TF1("f7", "gausn(0) + pol1(3)", 3280., 3316.); // clean peak, no background
  f7->SetParameters(540., 3296., 3., 0., 0.);
  h->Fit("f7", "LBR+");
  TF1 *f8 = new TF1("f8", "gausn(0) + pol1(3)", 3790., 3820.); // clean peak, no background
  f8->SetParameters(420., 3805., 3., 0., 0.);
  h->Fit("f8", "LBR+");
  TF1 *f9 = new TF1("f9", "gausn", 4795., 4835.); // clean peak, no background
  f9->SetParameters(500., 4815., 3.);
  h->Fit("f9", "LBR+"); // e.g. "BR+" or "LBR+"
  
  //Area1  
  std::cout << h->Integral(h->FindFixBin(410.), h->FindFixBin(422.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(831.), h->FindFixBin(843.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(1172.), h->FindFixBin(1184.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(1512.), h->FindFixBin(1526.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(2656.), h->FindFixBin(2673.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(2958.), h->FindFixBin(2976.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(3288.), h->FindFixBin(3307.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(3794.), h->FindFixBin(3814.)) << std::endl;
  std::cout << h->Integral(h->FindFixBin(4804.), h->FindFixBin(4826.)) << std::endl;
 
  TSpectrum *s = new TSpectrum(2*npeaks);
  
  Int_t nfound = s->Search(h,2,"",0.06);
  printf("Found %d candidate peaks to fit\n",nfound);

  s->Background(h->GetArray() + 1, n,
              10, TSpectrum::kBackDecreasingWindow,
              TSpectrum::kBackOrder8, kTRUE,
              TSpectrum::kBackSmoothing15, kTRUE);

//h->SetLineColor(kBlack);
//  h->Draw("");
//gPad->SetLogy(1);
//h->SetMaximum(3000.);//along Y

//h->SetAxisRange(0., 150.,"Y");


}