all the histograms are globally defined.

gain_measurement.cpp

@@ -4,9 +4,18 @@ const int namplitudes = 3;
 int nbins = 450;
 double xmin=850.0,xmax = 1750.0;
 
+
+
 TH1D *hist_255[namplitudes];
 
 
+hist_255[0] = new TH1D("hist_255_amp03","Threshold gain measurement",nbins, xmin, xmax);
+hist_255[1] = new TH1D("hist_255_amp02","Threshold gain measurement",nbins, xmin, xmax);
+hist_255[2] = new TH1D("hist_255_amp01","Threshold gain measurement",nbins, xmin, xmax);
+
+
+
+
 int colors[namplitudes]={kAzure,kRed,kViolet};
 int markers[namplitudes]={2, 3, 5};
 
@@ -20,20 +29,20 @@ double fitmax[namplitudes]={1700.,1420.,1240.};
 
 
 /////////////////////////////////////////////////////////////
- // The function fit_1d sets the cosmetics for the histograms/
- // and fits the histogram with modified erf function.       /
- /////////////////////////////////////////////////////////////
+// The function fit_1d sets the cosmetics for the histograms/
+// and fits the histogram with modified erf function.       /
+/////////////////////////////////////////////////////////////
 
 //TH1D *fit_1d(TH1D *hist_255, int i,int j, double low_limit, double up_limit)
 
 TH1D *fit_1d(TH1D *hist_255[namplitudes],int colors[namplitudes],int markers[namplitudes],int amp, double fitmin[namplitudes],double fitmax[namplitudes])
 {
-  
+
   hist_255[namplitudes]->GetXaxis()->SetTitle("Threshold");
   hist_255[namplitudes]->GetYaxis()->SetTitle("#signals above the threshold");
   hist_255[namplitudes]->SetMarkerColor(namplitudes);
   hist_255[namplitudes]->SetMarkerStyle(namplitudes);
-  
+
   // hist_255->SetMarkerStyle(i+1);
   // hist_255->SetMarkerColor(i+2);
 
@@ -43,7 +52,7 @@ TH1D *fit_1d(TH1D *hist_255[namplitudes],int colors[namplitudes],int markers[nam
   fitfunc->SetParNames("constant","mean","noise");
 
   //Assigning Initial values to the parameters
-  
+
   fitfunc->SetParameter(0,200.0);
 
   int lastbin1 = hist_255[namplitudes]->FindLastBinAbove(200);
@@ -70,18 +79,6 @@ TH1D *fit_1d(TH1D *hist_255[namplitudes],int colors[namplitudes],int markers[nam
 
 void gain_measurement()
 {
-  //Initialising the histograms.
-
- hist_255[0] = new TH1D("hist_255_amp03","Threshold gain measurement",nbins, xmin, xmax);
- hist_255[1] = new TH1D("hist_255_amp02","Threshold gain measurement",nbins, xmin, xmax);
- hist_255[2] = new TH1D("hist_255_amp01","Threshold gain measurement",nbins, xmin, xmax);
-
- cout<<"THe histograms initialised..."<<std::endl;
-  
-  /*TH1D *hist_255_amp03 = new TH1D("hist_255_amp03"," Threshold gain measurement",500,850,1750);
-  TH1D *hist_255_amp02 = new TH1D("hist_255_amp02"," Threshold gain measurement",500,850,1750);
-  TH1D *hist_255_amp01 = new TH1D("hist_255_amp01"," Threshold gain measurement",500,850,1750);*/
-
   //Initialising the trees.
 
   TTree *tree1 = new TTree("tree1", "tree1");
@@ -94,22 +91,19 @@ void gain_measurement()
   tree2->ReadFile("amp02_255_255.dat", "x/D:y/D");
   tree3->ReadFile("amp01_255_255.dat", "x/D:y/D");
   cout<<"The data is stored into the trees from the file..."<<std::endl;
-  
+
   tree1->Draw("x>>hist_255[0]","y","HIST P ");
   tree2->Draw("x>>hist_255[1]","y","HIST SAME P ");
   tree3->Draw("x>>hist_255[2]","y","HIST SAME P ");
   cout<<"The histograms are plotted.."<<std::endl;
 
   for (int iamp=0; iamp<3;iamp++)
-  { 
-    fit_1d(&hist_255[iamp],&colors[iamp],&markers[iamp],iamp, &fitmin[iamp], &fitmax[iamp]);
-   
-}
+    {
+      fit_1d(&hist_255[iamp],&colors[iamp],&markers[iamp],iamp, &fitmin[iamp], &fitmax[iamp]);
+
+    }
   cout<<"The fiiting function is called three times..."<<std::endl;
 
-  /* fit_1d(hist_255_amp03,1,3,1220.0,1700.0);
-  fit_1d(hist_255_amp02,2,2,1200.0,1420.0);
-  fit_1d(hist_255_amp01,3,1,1150.0,1240.0);*/
 
   //Drawing the legend
 
@@ -129,6 +123,15 @@ void gain_measurement()
 
 
 
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