I am trying to plot a probability density function showing the distribution of scattered protons passing through a planar detector. I think this should look somewhat like a Gaussian distribution. My data has x-y coordinates for each time a particle passes through the plane. I've plotted a histogram showing the distance of each data point from the origin (0,0). The plot dips in the center even though this is where the beam should be strongest. I think that the probability plot needs to be normalized based on the circumference. For example, if 100 protons strike the center (0,0) of the detector and 200 protons strike 10cm from the center, the center should show a higher density because the protons at 10cm are more spread out. Is there an easy way to correct for this in Matlab?