How can I plot point spread function?

Hi ,
I simulated SPECT camera using Gate simulation. I want to calculate and plot point spread function(psf) from root output of Gate simulation. For doing this work I need .C file which calculate and plot psf. But, I don’t know how can write the related comments. Would you please help me?

It depends which from have your data. If they are in, let say, vector of doubles you can use TGraph to draw them. There is many example here: … raphs.html

Thank you for sending graphs tutorial. but I know how to plot the graph, I need the commends ( orders) that calculate the point spread function and then plot it . In fact I need the commends in .C file for psf.