Circular or hemispherical surface area

I’m trying to create 3d histogram with either a circular or hemispherical surface area and randomly generate about 8-64 data events with 85 bins, but i can’t quite figure out how to do this. i’ve been able to generate a 3d cubic histogram with these parameters but only by fitting it with a gaussian distribution. is there any way i can create a circular plot with ROOT and have just random numbers without fitting it to a special distribution?
thanks for the help.

Your question is not clear, for example what do you mean by

[quote]randomly generate about 8-64 data events with 85 bins[/quote] ?
You can sample random numbers distributed at the surface of a sphere (see TRandom::Sphere) or a circle with TRandom::Circle