mxGetClassID (MATLAB Application Program Interface)

Get (as an enumerated constant) an mxArray's class

#include "matrix.h"
mxClassID mxGetClassID(const mxArray *array_ptr);

Arguments

array_ptr
Pointer to an mxArray.

Returns

The class (category) of the mxArray that array_ptr points to. Classes are:

mxCELL_CLASS
Identifies a cell mxArray.

mxSTRUCT_CLASS
Identifies a structure mxArray.

mxOBJECT_CLASS
Identifies a user-defined (nonstandard) mxArray.

mxCHAR_CLASS
Identifies a string mxArray; that is an mxArray whose data is represented as mxCHAR's.

mxSPARSE_CLASS
Identifies a sparse mxArray; that is, an mxArray that only stores its nonzero elements.

mxDOUBLE_CLASS
Identifies a numeric mxArray whose data is stored as double-precision, floating-point numbers.

mxSINGLE_CLASS
Identifies a numeric mxArray whose data is stored as single-precision, floating-point numbers.

mxINT8_CLASS

Identifies a numeric mxArray whose data is stored as signed 8-bit integers.

mxUINT8_CLASS

Identifies a numeric mxArray whose data is stored as unsigned 8-bit integers.

mxINT16_CLASS

Identifies a numeric mxArray whose data is stored as signed 16-bit integers.

mxUINT16_CLASS

Identifies a numeric mxArray whose data is stored as unsigned 16-bit integers.

mxINT32_CLASS

Identifies a numeric mxArray whose data is stored as signed 32-bit integers.

mxUINT32_CLASS

Identifies a numeric mxArray whose data is stored as unsigned 32-bit integers.

mxINT64_CLASS

Reserved for possible future use.

mxUINT64_CLASS

Reserved for possible future use.

mxUNKNOWN_CLASS = -1

The class cannot be determined. You cannot specify this category for an mxArray; however, mxGetClassID can return this value if it cannot identify the class.

Description

Use mxGetClassId to determine the class of an mxArray. The class of an mxArray identifies the kind of data the mxArray is holding. For example, if array_ptr points to a sparse mxArray, then mxGetClassID returns mxSPARSE_CLASS.

mxGetClassID is similar to mxGetClassName, except that the former returns the class as an enumerated value and the latter returns the class as a string.

Examples

Consider a MEX-file that can accept any kind of mxArray as its first input argument. If you intend to take action on the first input argument depending on its class, the first step is to call mxGetClassID.

void
mexFunction(int nlhs,mxArray *plhs[],int nrhs,const mxArray 
*prhs[])
{
 mxClassID  category; 

category = mxGetClassID(prhs[0]);
switch(category)  {
  case mxCHAR_CLASS:    analyze_string(prhs[0]);         break;
  case mxSTRUCT_CLASS:  analyze_structure(prhs[0]);      break;
  case mxSPARSE_CLASS:  analyze_sparse(prhs[0]);         break;
  case mxCELL_CLASS:    analyze_cell(prhs[0]);           break;
  case mxUNKNOWN_CLASS: mexWarnMsgTxt("Unknown class."); break;
  default:              analyze_numeric(prhs[0]);        break;
    }