I often want to do essentially the following:

mat <- matrix(0,nrow=10,ncol=1)
lapply(1:10, function(i) { mat[i,] <- rnorm(1,mean=i)})

But, I would expect that mat would have 10 random numbers in it, but rather it has 0. (I am not worried about the rnorm part. Clearly there is a right way to do that. I am worry about affecting mat from within an anonymous function of lapply) Can I not affect matrix mat from inside lapply? Why not? Is there a scoping rule of R that is blocking this?