Home Constructing lower triangular matrix
 I'm trying to construct a lower triangular matrix of a particular form, and as of right now, I'm using the following for loop: M = sparse(eye(DIM)); for k = 1 : DIM - 1 ak = -z*(1-z)^(k-1); M = M + sparse(diag(ak * ones(1, DIM - k), -k)); end  Basically, each diagonal from the main diagonal down is constant. I didn't include my definitions for DIM and z since they're not relevant to the construction of the matrix. Does anyone know a faster way to do this? Maybe a vectorized version?