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mxGetJc (C and Fortran) - Get jc array of sparse matrix

C Syntax

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

Fortran Syntax

mwPointer mxGetJc(pm)
mwPointer pm

Arguments

pm

Pointer to a sparse mxArray

Returns

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 usually means that an earlier call to mxCreateSparse failed.

Description

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.

C Examples

See fulltosparse.c in the matlabroot/extern/examples/refbook folder .

Additional examples:

• explore.c in the matlabroot/extern/examples/mex folder

• mxgetnzmax.c, mxsetdimensions.c, and mxsetnzmax.c in the matlabroot/extern/examples/mx folder

See Also

mxGetIr, mxGetNzmax, mxSetIr, mxSetJc, mxSetNzmax

mxGetIr (C and Fortran)

mxGetLogicals (C)

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