void fit_waveform11(void)
{
//=========Macro generated from canvas: c1/c1
//=========  (Wed Dec 17 14:51:38 2014) by ROOT version5.34/19
   TCanvas *c1 = new TCanvas("c1", "c1",1535,353,775,652);

gROOT->Reset();
//TTree *Bfield = (TTree *) gROOT->FindObject("Bfield");
gStyle->SetPalette(1,0);
gStyle->SetOptStat(kTRUE);
gStyle->SetOptFit(kTRUE);
gStyle->SetOptFit(1111);
gStyle->SetPadRightMargin(0.15);
gStyle->SetPadLeftMargin(0.15);
gStyle->SetPadBottomMargin(0.15);
gStyle->SetFillColor(0);
//


   c1->Range(-21.79487,-16.8,106.4103,95.2);
   c1->SetFillColor(0);
   c1->SetBorderMode(0);
   c1->SetBorderSize(2);
   c1->SetLeftMargin(0.17);
   c1->SetRightMargin(0.05);
   c1->SetBottomMargin(0.15);
   c1->SetFrameBorderMode(0);
   c1->SetFrameBorderMode(0);
   
   TH1F *hist11 = new TH1F("hist11","Ch=40,04,15",100,0,100);
   hist11->SetBinContent(1,4);
   hist11->SetBinContent(2,4);
   hist11->SetBinContent(3,5);
   hist11->SetBinContent(4,3);
   hist11->SetBinContent(5,3);
   hist11->SetBinContent(6,3);
   hist11->SetBinContent(8,4);
   hist11->SetBinContent(9,3);
   hist11->SetBinContent(10,2);
   hist11->SetBinContent(11,2);
   hist11->SetBinContent(13,3);
   hist11->SetBinContent(14,4);
   hist11->SetBinContent(15,2);
   hist11->SetBinContent(16,2);
   hist11->SetBinContent(17,3);
   hist11->SetBinContent(18,3);
   hist11->SetBinContent(19,5);
   hist11->SetBinContent(20,3);
   hist11->SetBinContent(21,3);
   hist11->SetBinContent(22,2);
   hist11->SetBinContent(23,4);
   hist11->SetBinContent(24,3);
   hist11->SetBinContent(25,2);
   hist11->SetBinContent(26,3);
   hist11->SetBinContent(27,3);
   hist11->SetBinContent(28,4);
   hist11->SetBinContent(29,5);
   hist11->SetBinContent(30,1);
   hist11->SetBinContent(31,3);
   hist11->SetBinContent(32,2);
   hist11->SetBinContent(33,4);
   hist11->SetBinContent(34,2);
   hist11->SetBinContent(35,3);
   hist11->SetBinContent(36,13);
   hist11->SetBinContent(37,31);
   hist11->SetBinContent(38,44);
   hist11->SetBinContent(39,44);
   hist11->SetBinContent(40,42);
   hist11->SetBinContent(41,40);
   hist11->SetBinContent(42,36);
   hist11->SetBinContent(43,33);
   hist11->SetBinContent(44,32);
   hist11->SetBinContent(45,26);
   hist11->SetBinContent(46,29);
   hist11->SetBinContent(47,25);
   hist11->SetBinContent(48,23);
   hist11->SetBinContent(49,20);
   hist11->SetBinContent(50,17);
   hist11->SetBinContent(51,19);
   hist11->SetBinContent(52,18);
   hist11->SetBinContent(53,18);
   hist11->SetBinContent(54,15);
   hist11->SetBinContent(55,13);
   hist11->SetBinContent(56,13);
   hist11->SetBinContent(57,13);
   hist11->SetBinContent(58,12);
   hist11->SetBinContent(59,12);
   hist11->SetBinContent(60,11);
   hist11->SetBinContent(61,9);
   hist11->SetBinContent(62,11);
   hist11->SetBinContent(63,8);
   hist11->SetBinContent(64,9);
   hist11->SetBinContent(65,8);
   hist11->SetBinContent(66,8);
   hist11->SetBinContent(67,6);
   hist11->SetBinContent(68,7);
   hist11->SetBinContent(69,8);
   hist11->SetBinContent(70,5);
   hist11->SetBinContent(71,8);
   hist11->SetBinContent(72,7);
   hist11->SetBinContent(73,4);
   hist11->SetBinContent(74,4);
   hist11->SetBinContent(75,3);
   hist11->SetBinContent(76,2);
   hist11->SetBinContent(77,3);
   hist11->SetBinContent(78,4);
   hist11->SetBinContent(79,4);
   hist11->SetBinContent(81,2);
   hist11->SetBinContent(82,3);
   hist11->SetBinContent(83,4);
   hist11->SetBinContent(84,1);
   hist11->SetBinContent(85,2);
   hist11->SetBinContent(86,2);
   hist11->SetBinContent(87,1);
   hist11->SetBinContent(88,2);
   hist11->SetBinContent(89,2);
   hist11->SetBinContent(90,2);
   hist11->SetBinContent(91,3);
   hist11->SetBinContent(92,4);
   hist11->SetBinContent(93,5);
   hist11->SetBinContent(94,5);
   hist11->SetBinContent(95,2);
   hist11->SetBinContent(96,3);
   hist11->SetBinContent(97,4);
   hist11->SetBinContent(98,4);
   hist11->SetBinContent(99,3);
   hist11->SetBinContent(100,5);
   hist11->SetMaximum(84);
   hist11->SetEntries(1100);
   // hist11->SetStats(0);
   hist11->SetLineColor(2);
   hist11->GetXaxis()->SetTitle("sample   (4 ns)");
   hist11->GetXaxis()->SetNdivisions(505);
   hist11->GetXaxis()->SetLabelFont(42);
   hist11->GetXaxis()->SetLabelSize(0.07);
   hist11->GetXaxis()->SetTitleSize(0.07);
   hist11->GetXaxis()->SetTitleFont(42);
   hist11->GetYaxis()->SetTitle("ADC value");
   hist11->GetYaxis()->SetNdivisions(505);
   hist11->GetYaxis()->SetLabelFont(42);
   hist11->GetYaxis()->SetLabelSize(0.07);
   hist11->GetYaxis()->SetTitleSize(0.07);
   hist11->GetYaxis()->SetTitleOffset(1.2);
   hist11->GetYaxis()->SetTitleFont(42);
   hist11->GetZaxis()->SetLabelFont(42);
   hist11->GetZaxis()->SetLabelSize(0.07);
   hist11->GetZaxis()->SetTitleSize(0.07);
   hist11->GetZaxis()->SetTitleFont(42);
   hist11->Draw("");
   
   TPaveText *pt = new TPaveText(0,0.9046154,0.40262,0.995,"blNDC");
   pt->SetName("title");
   pt->SetBorderSize(0);
   pt->SetFillColor(0);
   pt->SetFillStyle(0);
   pt->SetTextFont(42);
   TText *text = pt->AddText("Ch=40,04,15");
   pt->Draw();
   c1->Modified();
   c1->cd();
   c1->SetSelected(c1);

   // define pulse function

   Double_t xmin=0;
   Double_t xmax=100;

   TF1 *pulse = new TF1("pulse_func",pulse_func,xmin,xmax,5);
   Double_t mu=1/8.;    // unis of 1/x
   Double_t sigma=5;     // units of x 
   Double_t gain=500;   
   Double_t t0=40;
   Double_t pedestal=2;
   pulse->SetParameters(mu,sigma,gain,t0,pedestal);
   pulse->SetParNames("mu","sigma","gain","t0","pedestal");
  
   hist11->Fit(pulse);
   c1->SaveAs("fit_waveform11.pdf");

}
Double_t pulse_func (Double_t *x, Double_t *par) {

   Double_t mu=par[0];
   Double_t sigma=par[1];
   Double_t gain=par[2];
   Double_t t0=par[3];
   Double_t pedestal=par[4];
   Double_t x1=x[0]-t0;

   char string[256];

   Double_t func;
   Double_t amplitude;

   if (x1 < -20) {
           func = pedestal;
           }
   else if {

         Double_t arg = (mu*sigma*sigma-x1)/(sqrt(2)*sigma);
         Double_t arg2 = -mu*x1 +(mu*sigma)*(mu*sigma)/2;
         amplitude = (mu/2)* exp(arg2) *  TMath::Erfc(arg);
          func = gain * amplitude + pedestal;
  }
   
   /*sprintf (string,"x1=%f amplitude=%f mu=%f sigma=%f t0=%f pedestal=%f, func=%f\n",x1,amplitude,mu,sigma,pedestal,func);
   printf ("string=%s",string);*/

   return func;
}