Simple, accessing data in a TNtuple

ROOT
1

I know it’s possible to dump what I want of a TNtuple into a histogram, then use the histogram to get the information that I’m looking for, but this is a very simple case and I’m sure there’s an easier method.

If I print the TNtuple, I get:

[code]******************************************************************************
*Tree :RunInfo : Run-based Monitoring *
*Entries : 1 : Total = 5930 bytes File Size = 1089 *

  •    :          : Tree compression factor =   1.00                       *

*Br 0 :run : run/D *
*Entries : 1 : Total Size= 636 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
…
*Br 1 :startTime : startTime/D *
*Entries : 1 : Total Size= 672 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
…
*Br 2 :endTime : endTime/D *
*Entries : 1 : Total Size= 660 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
…
… (A few others I don’t need here)[/code]

I need the information contained in each entry of the three branches (if I’m using that term correctly), just three simple numbers.
Is there another way to get them other than the histogram method mentioned?

Thanks
Matt

2

TLeaf *leaf_run = tree->GetLeaf("run"); TLeaf *leaf_startTime = tree->GetLeaf("startTime"); TLeaf *leaf_endTime = tree->GetLeaf("endTime"); Long64_t nentries = tree->GetEntries(); for (Long64_t i=0;i<nentries;i++) { leaf_run->GetBranch()->GetEntry(i); leaf_startTime->GetBranch()->GetEntry(i); leaf_endTime->GetBranch()->GetEntry(i); double run = leaf_run->GetValue(); double startTime = leaf_startTime->GetValue(); double endTime = leaf_endTime->GetValue(); }

Rene