title: Cannot install package XML to R
body: <p>I need to install the package "XML" to R. It always reports "XML is not available for R(Version 3.1.1)"
  I have tried to download the .tar but it still did'n work. Can anyone help me to solve this?</p>
  
  <pre><code>&gt; install.packages("XML", repos = "http://www.omegahat.org/R");
  Warning in install.packages :
    cannot open: HTTP status was '404 Not Found'
  Warning in install.packages :
    cannot open: HTTP status was '404 Not Found'
  Warning in install.packages :
    unable to access index for repository http://www.omegahat.org/R/bin/windows/contrib/3.1
  
     package ‘XML’ is available as a source package but not as a binary
  
  Warning in install.packages :
    package ‘XML’ is not available (for R version 3.1.1)
  </code></pre>