TTree::Draw() loop over elements in std::vector<double>

Newbie
,
1

Dear experts

I want to draw some waveform in a ROOT file root -l somefile.root which needs loops over a std::vector stored in 1 entry.
I tried t->Draw("vector:Iteration$","Entry$==1", "APL"), just the same method as array, but it didn’t work. How can I achieve this with std::vector?

2

This should work:
t->Draw("v:Iteration$", "Length$(v) > 0", "APL", 1, 0); // nentries = 1, firstentry = 0

3

This gives a seg fault again… maybe the length of vector is too long that something run out of memory?

4

Try: t->Scan("Length$(v)");

5

The length is 12500 for every entry

6

12500 is a “small number” (no ROOT problems expected).

7

I just tried both local ROOT(v6-26-02) and ROOT on server (v6-22-02), it worked in local but gave seg fault on server…maybe it’s a version problem?

8

Maybe it’s some bug in ROOT 6.22 (try the newest ROOT version)?