Axis Extension for Sparse Histograms

General Chat
1

Is it possible to extend any of the axes of a sparse histogram ?
For example, consider the following example

void Test(){

   TRandom3 Random;

   double Min[]  = {0., 0.};
   double Max[]  = {1., 10.};
   int    NBin[] = {100, 100};

   THnSparseD Hist("Hist", "Hist2D", 2, NBin, Min, Max);
   Hist.GetAxis(1)->SetCanExtend(true);

   for(int Iter = 0; Iter < 1000; Iter++)
     Hist.Fill(std::vector<double>{Random.Rndm(), 20*Random.Rndm()}.data());

   Hist.SaveAs("Hist.root");

}

The values for filling the second axis are intentionally sampled from a uniform
distribution from the range (0, 20). Initially the axis range maximum is taken to
be 10 but a possible extension criterion is set. However, the output histogram
has the maximum still set at 10 and of course there are entries in the overflow
bin.

2

Hi,

Thanks for the post. Maybe I am wrong, but aren’t the dimension of the array with which you fill the histogram and the dimension of the sparse histogram not matching?

Cheers,
Danilo

3

Hi,

Can you kindly elaborate? Maybe I am missing something trivial here.
Pardon my naivety.