title: How to install Rmpfr on Ubuntu 18.04?
body: <p>After <code>install.packages("Rmpfr")</code> I'm getting this error</p>
  
  <pre><code>configure: error: Header file mpfr.h not found; maybe use
  --with-mpfr-include=INCLUDE_PATH
  ERROR: configuration failed for package ‘Rmpfr’
  </code></pre>
  
  <p>I typed the suggestion <code>--with-mpfr-include=INCLUDE_PATH</code> into the terminal w/o success.</p>