matlab - geometric random graph in a circle -

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i wanted generate set of coordinates distributed uniformly @ random within ball of radius r. there way in matlab without loops, in matrix-like form?

thanks

update: i'm sorry confusion. need generate n points uniformly @ random on circle of radius r, not sphere.

the correct answer here http://mathworld.wolfram.com/diskpointpicking.html. distribution known "disk point picking"


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