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mxGetN (C and Fortran)

Number of columns in array

C Syntax

#include "matrix.h"
size_t mxGetN(const mxArray *pm);

Fortran Syntax

mwPointer mxGetN(pm)
mwPointer pm



Pointer to an mxArray


Number of columns in the mxArray.


Call mxGetN to determine the number of columns in the specified mxArray.

If pm is an N-dimensional mxArray, mxGetN is the product of dimensions 2 through N. For example, if pm points to a four-dimensional mxArray having dimensions 13-by-5-by-4-by-6, mxGetN returns the value 120 (5 × 4 × 6). If the specified mxArray has more than two dimensions and you need to know exactly how many elements are in each dimension, call mxGetDimensions.

If pm points to a sparse mxArray, mxGetN still returns the number of columns, not the number of occupied columns.

    Note:   Fortran does not have an equivalent of size_t. mwPointer is a preprocessor macro that provides the appropriate Fortran type. The value returned by this function, however, is not a pointer.


See the following examples in matlabroot/extern/examples/refbook.

See the following examples in matlabroot/extern/examples/mx.

See the following examples in matlabroot/extern/examples/mex.

See the following examples in matlabroot/extern/examples/eng_mat.

Introduced before R2006a

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