title: Linker error with MathGL in XCode
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/12573816/what-is-an-undefined-reference-unresolved-external-symbol-error-and-how-do-i-fix">What is an undefined reference/unresolved external symbol error and how do I fix it?</a>  </p>
  </blockquote>
  
  
  
  <p>I'm trying to plot some matrices on 3D-graphs using MathGL with XCode. I managed (after a long day of frustration) to cmake, make and install MathGL (even had to install libpng, but that's a differents story). So, I managed to add the MathGL include path (<em>/usr/local/include</em>) to the XCode C++ project and it is working, since the autocompletion autocompletes the <code>mgl2/mgl.h</code> header file. Yet when I'm trying to build my code, which is only making one <code>mglGraph</code> member, I'm getting many linker errors:</p>
  
  <pre>
  Undefined symbols for architecture i386:
    "_mgl_create_graph", referenced from:
        _main in main.o
    "_mgl_delete_graph", referenced from:
        mglGraph::~mglGraph() in main.o
    "_mgl_set_font_size", referenced from:
        mglGraph::SetFontSizePT(double, int) in main.o
    "_mgl_use_graph", referenced from:
        mglGraph::~mglGraph() in main.o
  ld: symbol(s) not found for architecture i386
  </pre>
  
  <p>I know there are many posts out there (some even from me) listing problems with including correctly etc. but this one I just can't find any help for. So please anybody, how do I get this to work?</p>
  
  <p>I've tried changing/modifying the environment PATH and DYLD_* paths to include the <em>/usr/local/...</em> paths, but that didn't work. I've tried adding ALL folders in <em>/usr/local/</em> to the include path. I've tried compiling in 32 and 64 bit. I've tried including the <em>/usr/local/lib</em> in the library search path. But nothing worked. So please any help is very much appreciated.</p>
  
  <p>Regards
  Max</p>