Drawing two branches from tree with error bars

Hi all
I have a C macro which gives me a Tree is called “tree”, this Tree has many branches “” k1.mean ,time, p, t, k1.error_mean ,sigma …etc"", every branch has about 400 leafs.
How can I draw one branch vs other branch but with error bars which take values from third one.
as example: I want to draw ( k1.mean vs time ) with error bars which take their values from “k1.error_mean” branch.


I mean like this plot:


This is currently on our ‘long’ term plan. For now you will need to create the TGraphError by hand (possibly using the GetV1(), GetV2(), etc… functions after executing a TTree::Draw … Or use the result of MakeSelector or MakeProxy (see documentation for more details).