TTree::Draw() question

I have a large TTree in memory that I want to call Draw(“y:x”). In this case, “x” is monotonic increasing and the limits that TTree::Draw() chooses (based on default value TTree::fEstimate=1000000) are wrong. One possibility is to call TTree::SetEstimate(pt->GetEntries()), but that causes me to run out of memory for large TTrees (I have 1Gb ram + 1.5 Gb page file) The thing is, I already know what the x limits are - is there a way to tell this to root? I am using win32gdk v3.10/02 on win2k. Thank you.

see root.cern.ch/root/htmldoc/TTreeP … DrawSelect

look at : Saving the result of Draw to an histogram

Rene

Hi Rene,
Your suggestion works perfectly for 3.10/02, but has problem with 4.00/04 - please see examples that show displayed points being randomized within the histogram bins for 4.00/04. Is there a work-around if I move forward with version 4? Thanks

Ed