Assign the same variable to all elements of a Matrix

I would like to assign a variable to all elements of a Matrix without using a for loop to obtain a matrix M such that : M(nxn) = [x , x, x , x ,x ... ].

In my particular case x is an sdpvar and M is a matrix I use to set up the constraints of an optimisation problem.

Thank you

Answer 1

[Matt J]

I haven't worked with YALMIP, but can't you do

M=sdpvar(n);
M(:)=x;

[Adil Bendouro]

That is what I initially tried to do but it doesn't seem to work when the variables are multidimensional.

In my case I have:

M = sdpvar(10,10,10);

x = sdpvar(10,1);

M(:,:,:) = x;

which gives: In an assignment A(I) = B, the number of elements in B and I must be the same.

Answer 2

[John D'Errico]

As with Matt, I have not used the code, but this should work.

M = repmat(sdpvar(1,1),[10 10 10]);

[Adil Bendouro]

Unfortunately repmat didn't work for me. I believe that it is because it assigns copies of the variable x instead of the actual variable. Therefore the constraints of my linear program are not applied to x, which makes the optimisation problem unbounded.