Dynamically allocated array of histograms

ROOT
1

Hi,
in analysing a Tree, I have the need to create an array of histogram, or something equivalent, with a variable number of elements.
I have tried the following:


TH1F **h_pt_t_pdf=new TH1F*[num_pdf];
for(int i=0; i<num_pdf; i++){
        sprintf(h_name,"pt_t_pdf%i",i+1);
        h_pt_t_pdf[i]=new TH1F(h_name,"",n_pt_t,l_pt_t);
        }
where num_pdf is an int previously calculated, n_pt_t contains the number of bins and l_pt_t the edges of the histogram.

This works if the code is interpreted, while fails if compiled, returnig the error:

/home/matteo/codice_analisi/./analisi.cxx:450:9: error: ‘h_pt_t_pdf’ was not declared in this scope

I’m including the following headers:

#include <TH1.h> #include <TArray.h> #include<TObject.h> #include <TSystem.h> #include <TLorentzVector.h> #include <TMath.h> #include <TChain.h> #include <TFile.h> #include <TClonesArray.h>

but I think something is missing.
I know this approach is quite rough, but I was not able to find anything useful over the internet.
Any help will be really appreciated.
Thanks,
Matteo

2

I don’t see any problem in the code snippet that you show so I think you need to post the whole “analisi.cxx” here (so that we can try to recompile it).
See also: ROOT ACLiC Problems

3

Hi,
thanks for your reply, I was misleaded by the error output. The problem seems to be due to the fact I was including the header file ExRootSTDHEPReader.h instead of ExRootClasses.h.
Thanks again and sorry for opening this topic