title: Matconvnet error cl.exe not found
body: <p>I have installed MatConvNet from VLFeat and I am trying to compile it. But as I am trying to run <code>vl_compilenn</code> it shows the following error:</p>
  
  <pre><code>vl_compilenn
  Warning: CL.EXE not found in PATH. Trying to guess out of mex setup. 
  &gt; In vl_compilenn&gt;check_clpath (line 580)
    In vl_compilenn (line 413) 
  'cl.exe' is not recognized as an internal or external command, 
  operable program or batch file. 
  Error using vl_compilenn&gt;check_clpath (line 591)
  Unable to find cl.exe
  
  Error in vl_compilenn (line 413)
      check_clpath(); % check whether cl.exe in path
  </code></pre>