It seems like you want to change your random variable 'r' from uniform to Gaussian or Weibull. Currently, random variable 'r' is distributed uniformly in your code as
r = rand(L,L)
You might want to use normrnd or wblrnd to get Gaussian or Weibull random variables instead. You could do so by calling
r = normrnd(mu, sigma, L, L)
r = wblrnd(a, b, L, L)
where mu, sigma, a, and b represent the standard distribution parameters as in the documentation.
