How can I calculate point spread function?

Hi ,
I simulated SPECT camera using Gate. I want to calculate and plot point spread function(psf) from root output (.root file) of Gate simulation. For doing this work I need .C file which calculate a psf. I need the commends ( orders) in .C file that compute the point spread function and then plot it . what are the necessary comments for computing the point spread function in .C file?
Would you please help me?


you posted the same questions on all categories of the forum. I took the freedom to purge all but one posts: this strategy does not increase the likelihood of being better helped out.
It is hard to understand what you want to achieve from your text. Perhaps you can start from a general introduction to ROOT in order to be able to solve your particular problem. You can certainly have a look here to start: