Sparse identity matrix
S = speye(m,n)
S = speye([m n])
S = speye(n)
S = speye
S = speye(m,n) and
= speye([m n]) form an
1s on the main diagonal.
S = speye(n) abbreviates
S = speye returns the sparse
form of the 1-by-1 identity matrix.
I = speye(1000) forms the sparse representation
of the 1000-by-1000 identity matrix, which requires only about 16
kilobytes of storage. This is the same final result as
= sparse(eye(1000,1000)), but the latter requires eight
megabytes for temporary storage for the full representation.