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ROOT Version: Not Provided
Platform: Not Provided
Compiler: Not Provided
I have a ROOT file with a TNtuple.
I need to read off the day, hour, minute, second, and nanosecond from each row individually (i.e. I need to read off day/hour/min/sec/nsec from the first row, store each of those in a variable and do something with that, and then continue for the remaining rows). I’ve started out with the following code:
{
// Open the file containing the tree.
auto myFile = TFile::Open("./path/to/file.root");
if (!myFile || myFile->IsZombie()) {
return;
}
// Create a TTreeReader for the tree, for instance by passing the
// TTree's name and the TDirectory / TFile it is in.
TTreeReader myReader("N", myFile);
// The branch "px" contains floats; access them as myPx.
TTreeReaderValue<Float_t> myPx(myReader, "0");
// Loop over all entries of the TTree or TChain.
while (myReader.Next()) {
// Just access the data as if myPx and myPy were iterators (note the '*'
// in front of them):
std::cout << *myPx;
}
}
But I get the error:
Error in <TTreeReaderValueBase::CreateProxy()>: The tree does not have a branch called 0. You could check with TTree::Print() for available branches.