How to automate the construction of many matrices?

Hello, I am working with a ANN and need to create matrices which I am going to use in sim.net. I know how to automate e create one by one, but I have so may to create that I wouldn't worth all the worth. Maybe in for loop or any other advice would sufice.

The matrices have three lines, which here I call U, n and m. Each variable varies in a way. as U from 0 to 10 at 0.5 steps. n from 0 to 1 for each U and m from 0 to n fro each n. It goes something like:

% For u = 0 and n = 0:
U 0
n 0
m 0
% For u = 0 and n = 0.1:
U 0    0
n 0.1 0.1
m 0   0.1
...
% For u = 0 and n= 1:
U   0   0       0
n   1   1       1
m 0.0 0.1 ... 1.0

Then another U starts and n and m goes like the previous example.

Is it possible to automate it? I can't figure out how to do this.