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mxGetJc (C and Fortran)

Sparse matrix JC array

C Syntax

#include "matrix.h"
mwIndex *mxGetJc(const mxArray *pm);

Fortran Syntax

#include "fintrf.h"
mwPointer mxGetJc(pm)
mwPointer pm



Pointer to a sparse mxArray


Pointer to the first element in the jc array, if successful, and NULL in C (0 in Fortran) otherwise. Possible causes of failure include

  • Specifying a full (nonsparse) mxArray.

  • Specifying a value for pm that is NULL in C (0 in Fortran). This failure usually means that an earlier call to mxCreateSparse failed.


Use mxGetJc to obtain the starting address of the jc array. The jc array is an integer array having n+1 elements, where n is the number of columns in the sparse mxArray. The values in the jc array indirectly indicate columns containing nonzero elements. For a detailed explanation of the jc array, see mxSetJc.


See these examples in matlabroot/extern/examples/refbook:

See these examples in matlabroot/extern/examples/mx:

See these examples in matlabroot/extern/examples/mex:

Version History

Introduced before R2006a