How to draw data from multiple files onto one board

[ouyangzb]

• I want to plot the data of 100 files on a graph.
  I can put the data of 1 file on a graph.

[couet]

You can read the file in a loop and create a graph with each data common from the files add them in a multigraph and draw the multigraph.

[ouyangzb]

• I want to use Tree to draw this graph.Can you give me some help?

[couet]

tree->Draw("y:x","","L");

[ouyangzb]

I mean how do you use tree to loop through all the files .

[couet]

You should make a TChain with all the files.

[ouyangzb]

How to make a TChain to loop over all the files?
Can you show me some programs.
Thank you.

[Wile_E_Coyote]

TChain::TChain
TChain::Add

Header files for Trees

“Most recent” documentation about how to generate and use an “analysis skeleton”: TTree::MakeClass (see also “ROOT User’s Guide” → “Trees” → “Using TTree::MakeClass”) TTree::MakeSelector (see also “ROOT Primer” → “File I/O and Parallel Analysis” → “N-tuples in ROOT” → “For the advanced user: Processing trees with a selector script” and “ROOT User’s Guide” → “Trees” → “Using TTree::MakeSelector” and “ROOT User’s Guide” → “Example Analysis”) TTree::MakeProxy ROOT::RDataFrame (uses the T…