I have plot a data from file in a TMultiGraph, then i would like rotate the x label from horizontal to vertical position. I know the LabelsOption work only with alphanumerics, infact the data from text file are only number, but the result it is :
Warning in TAxis::Sort: Cannot sort. No labels.
the code is similar this:
TGraph *gr = new TGraph (“data.txt”);
where is the problem?
thank you to all