How to obtain the value of bin in a 2D-histogram

[Alex_Zhang]

Hi,
I have a 2D histogram. The x-axis range is -80 to 80 in steps of 1. The y-axis is the same as the x-axis. There are a total of 25600 bins. How can I obtain the values in each bin?

[vpadulan]

Dear @Alex_Zhang ,

You are probably looking for GetBinContent(binx, biny) ?

Cheers,
Vincenzo

[couet]

In case you need a running example showing how to use the method suggested by @vpadulan, here is one:

{
   // Create the fake histogram
   const int n=160;
   auto h = new TH2D("h","h",n,-80,80,n,-80,80);

   // Fill the fake histogram
   for (int i=1; i<=n; i++) {
      for (int j=1; j<=n; j++) {
         h->SetBinContent(i,j,i+j);
      }
   }

   // Read the bins of the fake histogram
   for (int i=1; i<=n; i++) {
      for (int j=1; j<=n; j++) {
         printf("Bin (%d,%d) contains %g\n",i,j,h->GetBinContent(i,j));
      }
   }
}

[Alex_Zhang]

Thank you for your reply.