Get the number of corresponding entries in Histogram?

General Chat
1

Hi Everyone,

I’m wondering if anybody knows how to get the content of entries in histogram? Say a histogram has 1 million entries(events), is there any function to get the number of corresponding entry, first one, second one…

for(Int_t i=1;i<=histo->GetEntries();i++)
{
histo->***???;
}

Thanks for your reply.

Regards,
Jeffrey

2

Hi Jeffrey,

I am afraid this is impossible by design. The histogram is the simplest way in which one can achieve an effective data reduction. The information you are looking for is not present. If you want to keep track of values of quantities entry by entry, the right data structure could be the TTree: root.cern.ch/doc/master/classTTree.html

Cheers,
Danilo