It seems like you want to generate two normally distributed random variables with correlation of 0.9. You can use the function "mvnrnd" from the statistics toolbox.
mu = [2 3]; % Vector of means. mean of amax is 2 and mean of mw is 3
sig = [1 0.9;0.9 1]; % Covariance matrix. Correlation is 0.9
nPts = 50; % Number of points you want to generate for each random variable
rVec = mvnrnd(mu,sig,nPts); % Generate the correlated random variables
Then you can extract "amax" and "mw" from "rVec":
amax = r(:,1);
mw = r(:,2);
And you can check the correlation between the two variables using the "corr" function and ensure that it is approximately 0.9
corr(amax,mw)
