Using the C Math Library

Determining Array Type

The MATLAB C Math Library includes several routines that allow you to determine the type of an array. Each routine tests for a particular type of array and returns 1 if the array being tested matches the indicated type and 0 (zero) otherwise.

Table 3-6: Array Type Routines

Array Type	Routine
Numeric array	mlfIsnumeric()
Character array	mlfIschar()
Sparse array	mlfIssparse()
Cell array	mlfIscell()
Cell array of strings	mlfIscellstr()
Structure	mlfIsstruct()

As an example, the following code uses the mlfIsnumeric() routine to test if a 2-by-2 array of ones is a numeric array.

mxArray *A = NULL;
mxArray *B = NULL;

/* Create two-dimensional array */
mlfAssign(&A, mlfOnes(mlfScalar(2),mlfScalar(2),NULL));

/* Determine if array is numeric */
mlfAssign(&B, mlfIsnumeric(A));

mlfFprintf(mlfScalar(1),                     /* stdout  */
           mxCreateString("Isnumeric returns %d.\n"), 
           B,                                /* array   */
           NULL);

mxDestroyArray(A); 
mxDestroyArray(B);

Because the array created is numeric, this code produces the following output:

Isnumeric returns 1.

Displaying MATLAB Arrays

Determining Array Size