Compiler / MEX using C help

Hi all,

I compiled a matlab function using the compiler toolbox into a dll, and I am trying to call it from my C program. For some reason, the program hangs at the mlfSimpsum(...) line below. Anyone see a mistake I made? The matlab function is very simple:

function c = simpsum(a,b)
c = a + b;
end

My C code:

#include <stdio.h>  
#include "main.h"
#include "SimpleSumDemo.h"

int main(void)
{

  mxArray *a_ptr, *b_ptr;
  mxArray *c_ptr=NULL;
  double *c;

  
  a_ptr =  mxCreateDoubleScalar(2);
  b_ptr = mxCreateDoubleScalar(7);
  

  /* Call the MCR and library initialization functions */
  if( !mclInitializeApplication(NULL,0) )
  {
    fprintf(stderr, "Could not initialize the application.\n");
    exit(1);
  }

  if (!SimpleSumDemoInitialize())
  {
    fprintf(stderr,"Could not initialize the library.\n");
    exit(1);
  }

  // Call the implementation function

  mlfSimpsum(1,&c_ptr,a_ptr,b_ptr);

  c =  mxGetPr(c_ptr);

  printf("2 + 7 = %d\n",&c);

  // Call the library termination function 
  SimpleSumDemoTerminate();

  // Clean up references (very important to prevent memory leaks!)
  mxDestroyArray(a_ptr);
  mxDestroyArray(b_ptr);
  mxDestroyArray(c_ptr);
  

  // Call the MCR termination function
  mclTerminateApplication();

  return 0;
}

[Leor Greenberger]

I moved

  a_ptr =  mxCreateDoubleScalar(2);
  b_ptr = mxCreateDoubleScalar(7);

to after the mclInitializeApplication and it now works. However, I get an output now of "2 + 7 = 1638144"

What am I doing wrong?

[Leor Greenberger]

Fixed! Although, I wonder if its possible to return a type int and not double?