How to subtract one gaussian from another?

Hello everyone,

I fitted two histos, and now I got two 2d gaussians and i want to subtract one from another. Can somebody explain how to do it? Or should I fill 2 more histos with some data using my fits and than subtract them?

TF2 *f = new TF2("f", "xygaus(0) - xygaus(5)", 0., 1., 0., 1.); f->Print();

grep -r xygaus ${ROOTSYS}/t[eu]*