Hi ! everyone , I want to write this matrix in matlab m.file!!

[Rik]

Have a read here (and here). It will greatly improve your chances of getting an answer.

Also, I doubt you are indeed using R11.1, so why did you enter that as the release you're using?

Answer 1

[Rik]

I suspect this is what you need:

C1=[zeros(p-m,n-p) eye(p-m)];