MATLAB Application Program Interface Reference | Help Desk |
mxIsEmpty
True ifmxArray
is empty
#include "matrix.h" bool mxIsEmpty(const mxArray *array_ptr);array_ptr
true
if the mxArray
is empty; otherwise, returns false
.
Use mxIsEmpty
to determine if an mxArray
is empty. An mxArray
is empty if the size of any of its dimensions is 0.
Attempts to access empty mxArray
cause undesirable behavior. To avoid accessing empty arrays, test them by calling mxIsEmpty
.
Note that mxIsEmpty
is not the opposite of mxIsFull
.
mxGetScalar
returns an indeterminate value if passed an empty mxArray
. mxIsEmpty
first:
void mexFunction(int nlhs,mxArray *plhs[],int nrhs,const mxArray *prhs[]) { double value; /* If array is empty, it would not be good to access it. */ if (mxIsEmpty(prhs[0])) mexErrMsgTxt("You cannot pass an empty array.\n"); else { value = mxGetScalar(prhs[0]); mexPrintf("First real value is %g\n", value); } }For an additional example, see
mxIsEmpty.c
in the mx
subdirectory of the examples
directory.
mxIsClass