External Interfaces Reference

mxCreateSparse

Create two-dimensional unpopulated sparse mxArray

Fortran Syntax

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

Arguments

m
   The desired number of rows.

n
   The desired number of columns.

nzmax
   The number of elements that mxCreateSparse should allocate to hold the pr, ir, and, if ComplexFlag = 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 double mxArray if successful, and 0 otherwise.

Description

Call mxCreateSparse to create an unpopulated sparse double 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 length nzmax.
• A pi array of length nzmax (but only if ComplexFlag is COMPLEX = 1).
• An ir array of length nzmax.
• A jc array of length n+1.

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

See Also

mxDestroyArray, mxSetNzmax, mxSetPr, mxSetIr, mxSetJc

mxCreateScalarDouble

mxCreateString

© 1994-2005 The MathWorks, Inc.