What is the correct way of using igl::repdiag?

[sebastianherscher]

I'm attemping to take the area matrix A (#Fx1) and expand it out into a diagonal matrix Ad, where the diagonal is A repeated three times. Is igl::repdiag the correct function to use here? If so, what is the correct way of using it?

I've tried the following:
Ad = igl::repdiag(A,3);
igl::repdiag(A,3,Ad);

in both cases, Ad, ends up being the same shape as A.

[jpanetta]

This doesn't seem to be what you want. You should look into vec.replicate<3, 1> and also vec.asDiagonal().

[sebastianherscher]

That is what I want. Thanks!