speye - sparse identity matrix
Isp=speye(nrows,ncols) returns a sparse identity matrix Isp with nrows rows, ncols columns. (Non square identity matrix have a maximal number of ones along the main diagonal).
Isp=speye(A) returns a sparse identity matrix with same dimensions as A . If [m,n]=size(A) , speye(m,n) and speye(A) are equivalent. In particular speye(3) is not equivalent to speye(3,3) .
eye(3,3)-full(speye(3,3))