title: Unable to install the "zoo" package (R version 2.15.1)
body: <p>I'm currently using R version 2.15.1, and I'm trying to install the "zoo" package, but I get the following error:  "package ‘zoo’ is not available (for R version 2.15.1)". Documentation says it depends on R>=2.10.0, are there any add-on packages it depends on that I need to install? I'm using the function "install.packages" to try to install this package, any thoughts thanks. </p>
  
  <pre><code>R version 2.15.1 (2012-06-22)
  Platform: x86_64-pc-linux-gnu (64-bit)
  
  locale:
  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C              
  [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8    
  [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8   
  [7] LC_PAPER=C                 LC_NAME=C                 
  [9] LC_ADDRESS=C               LC_TELEPHONE=C            
  [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       
  
  attached base packages:
  [1] splines   stats     graphics  grDevices utils     datasets  methods  
  [8] base     
  
  other attached packages:
  [1] ggplot2_0.9.0    lattice_0.20-6   nlme_3.1-104     MASS_7.3-19     
  [5] rms_3.5-0        Hmisc_3.9-3      survival_2.36-14
  
  loaded via a namespace (and not attached):
  [1] cluster_1.14.2     colorspace_1.1-1   dichromat_1.2-4    digest_0.5.2      
  [5] grid_2.15.1        memoise_0.1        munsell_0.3        plyr_1.7.1        
  [9] proto_0.3-9.2      RColorBrewer_1.0-5 reshape2_1.2.1     scales_0.2.0      
  [13] stringr_0.6        tcltk_2.15.1       tools_2.15.1 
  </code></pre>