mxSetM (External Interfaces Reference)

Set number of rows in mxArray

C Syntax

#include "matrix.h"
void mxSetM(mxArray *array_ptr, int m);

Arguments

m
The desired number of rows.

array_ptr
Pointer to an mxArray.

Description

Call mxSetM to set the number of rows in the specified mxArray. The term "rows" means the first dimension of an mxArray, regardless of the number of dimensions. Call mxSetN to set the number of columns.

You typically use mxSetM to change the shape of an existing mxArray. Note that mxSetM does not allocate or deallocate any space for the pr, pi, ir, or jc arrays. Consequently, if your calls to mxSetM and mxSetN increase the number of elements in the mxArray, then you must enlarge the pr, pi, ir, and/or jc arrays. Call mxRealloc to enlarge them.

If your calls to mxSetM and mxSetN end up reducing the number of elements in the mxArray, then you may want to reduce the sizes of the pr, pi, ir, and/or jc arrays in order to use heap space more efficiently. However, reducing the size is not mandatory.

Examples

See mxsetdimensions.c in the mx subdirectory of the examples directory. For an additional example, see sincall.c in the refbook subdirectory of the examples directory.

See Also

mxGetM, mxGetN, mxSetN

mxSetLogical (Obsolete) mxSetN