Draw a 2D plot from tree with weights

ROOT
1

Hi,
Assume I have a tree with three variables var1, var2, var3

I use the following code to draw a 2D plot:

tree -> Draw("var1:var2>>hh1");
How do I add a weight=var3 for this histogram?

Same question for plotting a profile:

tree -> Draw("var1:var2>>hh1", "", "prof");

Another tree-related question:
How do I set my own binning while Drawing from tree.
For example I want the binning twice smaller then root does automatically.

2

[quote]How do I add a weight=var3 for this histogram?

Same question for plotting a profile:
Code:
tree -> Draw(“var1:var2>>hh1”, “”, “prof”);
[/quote]Do:

tree -> Draw("var1:var2>>hh1", "var3", "prof");

[quote]Another tree-related question:
How do I set my own binning while Drawing from tree.
For example I want the binning twice smaller then root does automatically.[/quote]
Do

tree -> Draw("var1:var2>>hh1(50,xmin,xmax)", "var3", "prof"); see doc

Rene

3

Thanks a lot!

PS. reading docs became really confusing since the web-site has changed.
To many different documentation.
For example, I read that link:
http://root.cern.ch/drupal/content/how-read-tree

There is no binning and weighting things there.

4

well! the first thing to do when using TTree::Draw is to read the documentation of this function. see: root.cern.ch/root/html/TTree.html#TTree:Draw
and read the chapter about Trees in the Users Guide.

Rene