speye

Arguments

nrows

integer (number of rows)

ncols

integer (number os columns)

A

sparse matrix

sp

sparse identity matrix

Description

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(A) is equal to speye(m,n).

Hence, speye(3) is equal to speye(1,1), NOT to speye(3,3).

Examples

eye(3,3) - full(speye(3,3))

See also

• sparse — sparse matrix definition
• full — sparse to full matrix conversion
• eye — identity matrix
• diag — diagonal including or extracting
• toeplitz — Toeplitz matrix (chosen constant diagonal bands)
• spzeros — sparse zero matrix
• spones — sparse matrix