title: Error when using dgesv_: C:\...\Eye Tracker.exe not found
body: <p>I'm trying to solve a simple problem Ax = b using the dgesv_ function. However I've run into a problem I can't get past of. My code is:</p>
  
  <pre><code>#include &lt;cstdio&gt;
  #include &lt;f2c.h&gt;
  #include &lt;clapack.h&gt;
  
  void main(void)
  {
      /* 3x3 matrix A
       * 76 25 11
       * 27 89 51
       * 18 60 32
       */
      double A[9] = {76, 27, 18, 25, 89, 60, 11, 51, 32};
      double b[3] = {10, 7, 43};
  
      int N = 3;
      int nrhs = 1;
      int lda = 3;
      int ipiv[3];
      int ldb = 3;
      int info;
  
      dgesv_(&amp;N, &amp;nrhs, A, &amp;lda, ipiv, b, &amp;ldb, &amp;info);
  
  }
  </code></pre>
  
  <p>I think the code is correct, however, whenever I run it I get the following error:</p>
  
  <pre><code>LINK : C:\...\Eye Tracker.exe not found or not built by the last incremental link; performing full link
  1&gt;     Creating library C:\...\Eye Tracker\Debug\Eye Tracker.lib and object C:\Users\Daniel\documents\visual studio 2010\Projects\Eye Tracker\Debug\Eye Tracker.exp
  1&gt;ellipse_fit.obj : error LNK2019: unresolved external symbol "void __cdecl dgesv_(int const *,int const *,double *,int const *,int *,double *,int const *,int *)" (?dgesv_@@YAXPBH0PAN0PAH102@Z) referenced in function "void __cdecl ttt(void)" (?ttt@@YAXXZ)
  1&gt;C:\Users\Daniel\documents\visual studio 2010\Projects\Eye Tracker\Debug\Eye Tracker.exe : fatal error LNK1120: 1 unresolved externals
  </code></pre>