Error on drawing from a simple ntuple and some beginner questions

[ExtremeMango]

I followed what was done here except I avoid using a pointer:

Reading & Analysing ascii data in TTree

Dear Root Gurus, I’m trying to do some analysis on 4 ascii datafiles, each with 25 columns of data. Each column represents a variable. The variables in all 4 data files have identical names but differ only in value. I tried to read the data into a Tree using TNtuple *ntuple = new TNtuple("name","title", v1:v2:v3:....v25); ntuple->Fill(v1,v2,v3,..v25); as described in the tutorial basic.C. I get an error message which I traced to i.e. it seems that the Fill function cannot read in more that…