Probably distribution inside a circle

[night depot]

How would you go about plotting the probability distribution of some particles inside a circle?
I'd like to check if the code I've got gives the particle an equal probability of being everywhere but if I just plot the distance from centre and probability, since the area increases with r, it looks like the particle has more chance of being away from the centre.
If that makes sense, since the area will increase as 2pir