title: include cairo R on a mac
body: <p>I'm trying to use 'Cairo' package in Rstudio, using the command <code>install.packages('Cairo')</code>
  and it goes through with no problem. 
  I get this message- </p>
  
  <pre><code>The downloaded binary packages are in
  /var/folders/xn/c1nj85gx62b89876s15sbv9h0000gn/T//RtmpK9JM0l/downloaded_packages 
  </code></pre>
  
  <p>The package appears in the packages list, but when I try to include the package using <code>library(Cairo)</code> or <code>library('Cairo')</code> 
  I get this error mesage-</p>
  
  <pre><code>Error : .onLoad failed in loadNamespace() for 'Cairo', details:
    call: dyn.load(file, DLLpath = DLLpath, ...)
    error: unable to load shared object '/Library/Frameworks/R.framework/Versions/3.3/Resources/library/Cairo/libs/Cairo.so':
    dlopen(/Library/Frameworks/R.framework/Versions/3.3/Resources/library/Cairo/libs/Cairo.so, 6): Library not loaded: /opt/X11/lib/libXrender.1.dylib
    Referenced from: /Library/Frameworks/R.framework/Versions/3.3/Resources/library/Cairo/libs/Cairo.so
    Reason: image not found
  Error: package or namespace load failed for ‘Cairo’
  </code></pre>
  
  <p><code>sessionInfo()</code></p>
  
  <pre><code>R version 3.3.1 (2016-06-21)
  Platform: x86_64-apple-darwin13.4.0 (64-bit)
  Running under: OS X 10.11.6 (El Capitan)
  
  locale:
  [1] he_IL.UTF-8/he_IL.UTF-8/he_IL.UTF-8/C/he_IL.UTF-8/he_IL.UTF-8
  
  attached base packages:
  [1] stats4    parallel  stats     graphics  grDevices utils     datasets  methods  
  [9] base     
  
  other attached packages:
  [1] GenomicRanges_1.24.2 GenomeInfoDb_1.8.3   IRanges_2.6.1       
  [4] S4Vectors_0.10.2     ggbio_1.20.2         BiocGenerics_0.18.0 
  [7] ggplot2_2.1.0        BiocInstaller_1.22.3 shiny_0.13.2        
  </code></pre>
  
  <p>I'm not sure why is this happening, any help?
  Thanks!</p>