title: add armadillo libraries to g++ compiler in linux
body: <p>I am trying to install a C++ library (<a href="http://arma.sourceforge.net/" rel="nofollow">armadillo</a>) in a unix cluster where I do not have root permissions.</p>
  
  <p>I managed to compile the C++ libraries without user permissions by running the following make command: </p>
  
  <pre><code>make install DESTDIR=my_usr_dir
  </code></pre>
  
  <p>But then in the armadillo readme file it says:</p>
  
  <p>where "my_usr_dir" is for storing C++ headers and library files. Make sure your C++ compiler is configured to use the sub-directories present within this directory.</p>
  
  <p>The compiler the armadillo uses to install the libraries is gcc-4.8.1. I am not sure where the compiler was installed but it's loaded when I start my session in the unix cluster.</p>
  
  <p>After installing armadillo I am trying to compile open source code that uses the armadillo libraries.  This open source code also has a makefile.</p>
  
  <p>However, when I go to the open source code and I type in:</p>
  
  <pre><code>make 
  </code></pre>
  
  <p>it calls g++.  How can I make sure g++ will recognize the armadillo libraries previously installed in my_usr_dir?</p>
  
  <p>Currently I get the following error if I go to src and then type make:</p>
  
  <pre><code>opencode.cpp:28:21: fatal error: armadillo: No such file or directory
   #include &lt;armadillo&gt;
                       ^
  compilation terminated.
  make: *** [mmcollapse] Error 1
  </code></pre>