How to fill matrix with random numbers in R?

Question

expand.grid(i=rexp(5,rate=0.1))

It creates just one col but is there some way to multiply this easily to 5 cols? I mean the matlab-way-of-doing-things

Answer 1

?matrix will tell you lots! and rexp is the function to generate a random exponential distribution.

mat <- matrix(data = rexp(200, rate = 10), nrow = 10, ncol = 20)