title: How to install package when HTTP status was '404 Not Found'
body: <p>I am having a rather tough time with the fields package.</p>
  
  <pre><code>sessioninfo()
  R version 3.1.0 (2014-04-10)
  Platform: x86_64-apple-darwin13.1.0 (64-bit)
  
  locale:
  [1] en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8
  
  attached base packages:
  [1] stats     graphics  grDevices utils     datasets  methods   base    
  </code></pre>
  
  <p>form the <a href="http://cran.r-project.org/web/packages/fields/index.html" rel="noreferrer">url</a> everything seems to be fine and <code>fields</code> depends on > or = to 3.0</p>
  
  <p>I have tried downloading the package with <code>install.packages</code> but I get a rather strange result i have not seen before:</p>
  
  <pre><code>trying URL 'http://cran.ma.imperial.ac.uk/bin/macosx/mavericks/contrib/3.1/fields_7.1.tgz'
  Error in download.file(url, destfile, method, mode = "wb", ...) : 
    cannot open URL 'http://cran.ma.imperial.ac.uk/bin/macosx/mavericks/contrib/3.1/fields_7.1.tgz'
  In addition: Warning message:
  In download.file(url, destfile, method, mode = "wb", ...) :
    cannot open: HTTP status was '404 Not Found'
  Warning in download.packages(pkgs, destdir = tmpd, available = available,  :
    download of package ‘fields’ failed
  </code></pre>
  
  <p>I have also tried downloading using the url for the files directly for both <code>7.1</code> and <code>6.9.1(mavericks)</code>:</p>
  
  <pre><code>packageurl &lt;- "http://cran.r-project.org/bin/macosx/mavericks/contrib/3.1/fields_6.9.1.tgz"
  &gt; install.packages(packageurl, contriburl=NULL, type="source")
  Warning message:
  package ‘http://cran.r-project.org/bin/macosx/mavericks/contrib/3.1/fields_6.9.1.tgz’ is not available (for R version 3.1.0) 
  
  &gt; packageurl &lt;- "http://cran.r-project.org/bin/macosx/contrib/3.1/fields_7.1.tgz"
  &gt; install.packages(packageurl, contriburl=NULL, type="source")
  Warning message:
  package ‘http://cran.r-project.org/bin/macosx/contrib/3.1/fields_7.1.tgz’ is not available (for R version 3.1.0) 
  </code></pre>
  
  <p>and running all the <code>.R</code> files from the unpacked <code>.tar</code> file</p>
  
  <pre><code>sapply(list.files(pattern="[.]R$", path="........fields/R/", full.names=TRUE), source)
  </code></pre>
  
  <p>but if I do this then functions do not work e.g.</p>
  
  <pre><code>&gt; rdist(c(1,1))
  Error in .Fortran("radbas", PACKAGE = "fields", nd = as.integer(d), x1 = as.double(x1),  : 
    "radbas" not available for .Fortran() for package "fields"
  </code></pre>
  
  <p><strong>QUESTION</strong> -  This seems weird that fields is not available for R 3.1 as it is an intensely used package by many,  any ideas on solving this?</p>