2D array and TMatrix

ROOT
1

Hi all,
I am writing a program where I use an 2D array:

...
Int_t N_ev=2608;
Int_t N_set=100;

Float_t poisson[N_set][N_ev];

for (int i=0; i<N_set; i++)
  {
     for (int j=0; j<N_ev; j++)
      {
        poisson[i][j]= TMath::Poisson(j,3.87);
	mean[i] += (poisson[i][j])/(N_ev);
      }
  }
...

If the value of N_set is 100, it works, but if I put 1000, I obtain:

Error: Array index out of range poisson -> [260801]   valid upto poisson[99][2607]

and I don’t understand where is the mistake.

I try to use TMatrix and it works, but I don’t understand how I get a element of the matrix.

Could you answer to these my two question, please?
Thanks
Ciccio

2

[quote]and I don’t understand where is the mistake. [/quote]I think this is because you are reloading the script in the same session and CINT still knows about the old (smaller) definition).

[quote]I try to use TMatrix and it works, but I don’t understand how I get a element of the matrix.
[/quote]Use mymatrix(i,j);

Cheers,
Philippe.

3

Hi,
thank you very much
Ciccio