|Computes a sparse or full identity matrix|
|Other toolboxes required||none|
|Function category||Helper functions|
|This is a helper function that only exists to aid other functions in QETLAB. If you are an end-user of QETLAB, you likely will never have a reason to use this function.|
iden is a function that computes the identity matrix of the desired size, which is either full or sparse.
- ID = iden(DIM,SP)
- DIM: The number of rows (or equivalently, columns) that ID will have.
- SP: A flag (either 1 or 0) indicating whether ID should or should not be sparse.
Full and sparse versions of the 2-by-2 identity matrix:
Click on "expand" to the right to view the MATLAB source code for this function.
%% IDEN Computes a sparse or full identity matrix
% This function has two required arguments:
% DIM: the number of rows (or columns) of the identity matrix
% SP: a flag (1 or 0)
% ID = iden(DIM,SP) returns the DIM-by-DIM identity matrix. If SP = 0
% then ID will be full. If SP = 1 then ID will be sparse.
% Only use this function within other functions to easily get the correct
% identity matrix. If you always want either the full or the sparse
% identity matrix, just use MATLAB's built-in eye or speye function.
% URL: http://www.qetlab.com/iden
% requires: nothing
% author: Nathaniel Johnston (firstname.lastname@example.org)
% package: QETLAB
% last updated: November 28, 2012
function id = iden(dim,sp)
id = speye(dim);
id = eye(dim);