title: RNCEP R package causing new R session, not working
body: <p>I'm working in R using the <code>RNCEP</code> package to download reanalysis data. </p>
  
  <p>If I run</p>
  
  <pre><code>install.packages("RNCEP", dependencies=TRUE)
  library(RNCEP)
  </code></pre>
  
  <p>I get a behavior that I've never seen before in any package: an XQuartz window opens up. If I try to run any of the example scripts, I get an error message that looks like</p>
  
  <blockquote>
    <p>Error in NCEP.gather.pressure(variable = variable, months.minmax = months.minmax,  :There is a problem connecting to the NCEP database with the information provided.</p>
  </blockquote>
  
  <p>If I close the XQuartz window, my RStudio session crashes.</p>
  
  <p>I've tried removing and reinstalling multiple times, but I get same results every time. According to <a href="https://sites.google.com/site/michaelukemp/rncep" rel="nofollow">the developer's web site</a>, </p>
  
  <blockquote>
    <p>For Unix-alike (e.g. Mac and Linux) users running R 2.8.0 or greater, loading of the RNCEP package may fail if Tcl/Tk version >= 8.4 is not installed (see section A.2.1 of R Installation and Administration).  For Mac OS X users, Tcl/Tk may be obtained here.</p>
  </blockquote>
  
  <p>I'm running OSX El Capitan, so that may have something to do with my problem. I ran <code>brew cask install tcl</code> to get tcl through homebrew, but that hasn't had an impact.</p>
  
  <p>FWIW: my R version information</p>
  
  <pre><code>&gt;version
                 _                                          
  platform       x86_64-apple-darwin15.3.0                  
  arch           x86_64                                     
  os             darwin15.3.0                               
  system         x86_64, darwin15.3.0                       
  status         Revised                                    
  major          3                                          
  minor          2.4                                        
  year           2016                                       
  month          03                                         
  day            16                                         
  svn rev        70336                                      
  language       R                                          
  version.string R version 3.2.4 Revised (2016-03-16 r70336)
  nickname       Very Secure Dishes         
  </code></pre>
  
  <p>An update: I've tried running R both through homebrew:</p>
  
  <pre><code>brew tap caskroom/cask
  brew install R --with-openblas
  brew install Caskroom/cask/rstudio
  </code></pre>
  
  <p>and by fully removing those options and installing from the web site (I've heard of people having trouble with homebrew R and Rstudio). Same results.</p>
  
  <p>However, the <code>RNCEP</code> packages works if I'm running R in terminal for some reason.</p>