visual studio 2010 c++ to matlab engine link errors

Hi All,

I'd appreciate some help here, getting kinda frustrated after googling and troubleshooting my problem here.

I am trying to run an example that communicates to matlab via matlab engine from c++ but continually encounter errors. Here is what i'm doing step by step:

1.launch vs2010. New project , Win32 project (i understood because of matlab GUI i need win32 and not console),empty project.

2.New source file with this code:

#include<iostream>
#include<cmath>

#ifdef _CHAR16T     //redifined definition problem
#define CHAR16_T
#endif

#include "engine.h"

using namespace std;

int main(){
  Engine *ep = engOpen(NULL);
  double x[1000];
  double y[1000];
  double z[1000];

    double t = 0;
    const double dt = 0.001;
    int i,j;
    double a,b;

    mxArray *z_array = mxCreateDoubleMatrix(1000,1,mxREAL);
    mxArray *a_array = mxCreateDoubleMatrix(   1,1,mxREAL);
    mxArray *b_array = mxCreateDoubleMatrix(   1,1,mxREAL);

    double *pz = mxGetPr(z_array);
    double *pa = mxGetPr(a_array);
    double *pb = mxGetPr(b_array);

    for (i=0;i<1000;i++){
      x[i] = cos(2*3.14*t);
      y[i] = sin(2*3.14*t);
      t+=dt;
    }

    a = 1; 
    b = 0;
    for (j=0;j<100;j++){
      for(i=0;i<1000;i++){
        z[i] = a*x[i] + b*y[i];
        pz[i] = z[i];
      }
      pa[0] = a;
      pb[0] = b;

      engPutVariable(ep,"z",z_array);
      engPutVariable(ep,"a",a_array);
      engPutVariable(ep,"b",b_array);
    //  engEvalString(ep,"testPlot");

      a = a - 0.01;
      b = b + 0.01;
    }

    engClose(ep);

    return 0;
  }

3.Add header file engine.h from C:\Program Files\MATLAB\R2010a\extern\include

4.Configure project properties: a. C/C++ \ General \ Additional Include directories: C:\Program Files\MATLAB\R2010a\extern\include b. Linker \ General \ Additional Library Directories: C:\Program Files\MATLAB\R2010a\extern\lib\win64\microsoft c.Linker \ Input \ Additional Dependencies : libeng.lib libmat.lib libmex.lib libmx.lib

The compiler error I receive are:

1>maindemo.obj : error LNK2019: unresolved external symbol engClose referenced in function _main 1>maindemo.obj : error LNK2019: unresolved external symbol _engPutVariable referenced in function _main 1>maindemo.obj : error LNK2019: unresolved external symbol _mxGetPr referenced in function _main 1>maindemo.obj : error LNK2019: unresolved external symbol _mxCreateDoubleMatrix_730 referenced in function _main 1>maindemo.obj : error LNK2019: unresolved external symbol _engOpen referenced in function _main 1>MSVCRTD.lib(crtexew.obj) : error LNK2019: unresolved external symbol _WinMain@16 referenced in function __tmainCRTStartup 1>C:\Users\Et\Documents\Work\win32\GettingStarted\cpp2matlab\c2mdemo\Debug\c2mdemo.exe : fatal error LNK1120: 6 unresolved externals

More Info:

I am running windows 7 64. Matlab 2010a. Visual studio 2010.

My Environmental variables have PATH with: C:\Program Files\MATLAB\R2010a\runtime\win64; C:\Program Files\MATLAB\R2010a\bin; C:\Program Files\MATLAB\R2010a\bin\win64;

Ofcourse if more information is needed just let me know, I am not a computer engineer , or programmer by education , so pls be gentle with me ;). Anyway , as said before Id really appreciate any help on this issue.... tx, Etamar.

Answer 1

[Kaustubha Govind]

If you are using 64-bit MATLAB, all the libraries in C:\Program Files\MATLAB\R2010a\extern\lib\win64\microsoft are also 64-bit binaries. Therefore, you need to configure your Visual Studio project for a win64 application, not win32.

[Etamar]

Hi,

Thank you for your replay,

But what do you mean configure my project for for a win 64 not a win32?>

When I launch new project I have two options:

Win32 console application

or

Win32 Project

I understood that Win32 Project was needed for matlab GUI to use WinAPI.

Answer 2

[Etamar]

Update:

At configuration manager in VS, I added to Platform x64, and now my link errors are different , they are:

1>MSVCRTD.lib(crtexew.obj) : error LNK2019: unresolved external symbol WinMain referenced in function __tmainCRTStartup 1>C:\Users\Et\Documents\Work\win32\GettingStarted\cpp2matlab\c2mdemo\x64\Debug\c2mdemo.exe : fatal error LNK1120: 1 unresolved externals

What else am i missing?

[Kaustubha Govind]

You should select the project type as a Console Application instead of a Windows application. See http://support.microsoft.com/kb/131204

[israel Ohiofudu]

Hello,

In my case I have only the 64x runtime with Visual Studio 2012.

I have the same Link Error LNK2019.

[Kaustubha Govind]

israel: Is the error about WinMain or a different symbol?

Answer 3

[Vijay Kumar Polimeru]

Hope you have solved the problem. If not the answer written by Jav_Rock in this link may help you to debug the errors...