Iden

iden
Computes a sparse or full identity matrix
Other toolboxes required	none
Function category	Helper functions

iden is a function that computes the identity matrix of the desired size, which is either full or sparse.

Syntax

• ID = iden(DIM,SP)

Argument descriptions

• 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.

Examples

Full and sparse versions of the 2-by-2 identity matrix:

>> iden(2,0)

ans =

     1     0
     0     1

>> iden(2,1)

ans =

   (1,1)        1
   (2,2)        1

Notes

This function is only meant to simplify code within other functions. If you always want either the full or the sparse identity matrix, just use MATLAB's built-in eye or speye function.

Source code

Click on "expand" to the right to view the MATLAB source code for this function.