I am hoping to create 3 (non-negative) quasi-random numbers that sum to one, and repeat over and over. Basically I am trying to partition something into three random parts over many trials. While I am aware of a= runif(3,0,1) I was thinking that I could use 1-a as the max in the next run if, but it seems messy. But these of course don't sum to one. Any thoughts, oh wise stackoverflow-ers?