How to set Xmin, Ymin, Xmax, Xmin in graph.C

Hi,

I believe you can use SetLimits in TAxis for the two axis:

https://root.cern.ch/doc/master/classTAxis.html#aa56ec858687dad0b58ca0cf939e7c79b

So you can do gr->GetXaxis()->SetLimits(xmin, xmax) and similarly for y axis.