gistfile1.c

#include "mex.h"

/* Input Arguments */
#define X1   prhs[0]
#define X2   prhs[1]

/* Output Arguments */
#define Y    plhs[0]

void mexFunction( int nlhs, mxArray *plhs[], 
                  int nrhs, const mxArray *prhs[] )
{        
	printf("adder\n");
    /* Check for proper number of arguments */    
    if (nrhs != 2) { 
        mexErrMsgTxt("Two input arguments required."); 
    } else if (nlhs > 1) {
        mexErrMsgTxt("Too many output arguments."); 
    } else {
		printf("Adder from MEX function\n");
	} 
       
	//Allocate ouptut
	Y = mxCreateNumericMatrix(1, 1, mxDOUBLE_CLASS, mxREAL);
	//Adder function
    *mxGetPr(Y) = *mxGetPr(X1) + *mxGetPr(X2); 
}