MATLAB Application Program Interface Reference

Create a 2-dimensional unpopulated sparse mxArray

integer*4 function mxCreateSparse(m, n, nzmax, ComplexFlag)
integer*4 m, n, nzmax, ComplexFlag

Arguments

The desired number of rows.

The desired number of columns.

nzmax

The number of elements that mxCreateSparse should allocate to hold the pr, ir, and, if COMPLEX = 1, pi arrays. Set the value of nzmax to be greater than or equal to the number of nonzero elements you plan to put into the mxArray, but make sure that nzmax is less than or equal to m*n.

ComplexFlag

Specify REAL = 0 if the data has no imaginary components; specify
COMPLEX = 1 if the data has some imaginary components.

Returns

An unpopulated, sparse mxArray if successful, 0 otherwise.

Description

Call mxCreateSparse to create an unpopulated sparse mxArray. The returned sparse mxArray contains no sparse information and cannot be passed as an argument to any MATLAB sparse functions. In order to make the returned sparse mxArray useful, you must initialize the pr, ir, jc, and (if it exists) pi array.

mxCreateSparse allocates space for

A pr array of m-by-n elements.
A pi array of m-by-n elements (but only if ComplexFlag is COMPLEX = 1).
An ir array of nzmax elements.
A jc array of m elements.

When you finish using the sparse mxArray, call mxFreeMatrix to reclaim all its heap space.