Recovering the values used in a profile graph

ROOT
1

Hi Rooters,

I would like to recover the values used when plotting a profile graph.
For example ;

t->Draw("Elabl:Al>>elabahistolt","","same prof l hist");

Elabl and Al are 2 branches of a tree. I would like to recover the values used to draw the profile, in a text file. Is it possible?

Thanks

2

see documentation of TTree::Draw, eg
root.cern.ch/root/html/TTreePlay … DrawSelect
in particular this section

[code] How to obtain more info from TTree::Draw

Once TTree::Draw has been called, it is possible to access useful
information still stored in the TTree object via the following functions:
-GetSelectedRows() // return the number of entries accepted by the
//selection expression. In case where no selection
//was specified, returns the number of entries processed.
-GetV1() //returns a pointer to the double array of V1
-GetV2() //returns a pointer to the double array of V2
-GetV3() //returns a pointer to the double array of V3
-GetW() //returns a pointer to the double array of Weights
//where weight equal the result of the selection expression.
where V1,V2,V3 correspond to the expressions in
TTree::Draw(“V1:V2:V3”,selection);

Example:
Root > ntuple->Draw(“py:px”,“pz>4”);
Root > TGraph *gr = new TGraph(ntuple->GetSelectedRows(),
ntuple->GetV2(), ntuple->GetV1());
Root > gr->Draw(“ap”); //draw graph in current pad
creates a TGraph object with a number of points corresponding to the
number of entries selected by the expression “pz>4”, the x points of the graph
being the px values of the Tree and the y points the py values.
[/code]

Rene