title: Installed packages in R
body: <p>K, it seems like I have a problem.
  I'm trying to access the Hmisc package, which of course is installed.
  And i get this error:</p>
  
  <p>in Rstudio:</p>
  
  <blockquote>
    <p>Loading required package: ggplot2
        Error in loadNamespace(j &lt;- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) : 
          there is no package called ‘Rcpp’
        Error: package ‘ggplot2’ could not be loaded</p>
  </blockquote>
  
  <p>in R:</p>
  
  <blockquote>
    <p>Error in unloadNamespace(package) : 
          namespace ‘ggplot2’ is imported by ‘caret’ so cannot be unloaded
        Error in library(pkg, character.only = TRUE, logical.return = TRUE, lib.loc = lib.loc,  : 
          Package ‘ggplot2’ version 1.0.1 cannot be unloaded</p>
  </blockquote>
  
  <p>I already have ggplot2 and caret but I wasn't sure about Rcpp, so I decided to install both. For that I used the function:  install.packages('', dep = TRUE)
  The ggplot 2 installs smoothly and the same with Rcpp but with a warning:</p>
  
  <blockquote>
    <p>Warning in install.packages :
          cannot remove prior installation of package ‘Rcpp’</p>
  </blockquote>
  
  <p>Same warning in caret.</p>
  
  <p>Anyway, nothings changes when I try to access the Hmisc library.</p>
  
  <p>Maybe it helps to say I updated both (R and RStudio) few days ago with the latest versions and the installed packages are in my working directory. 
  Something was/is definitely wrong, cause I got some error running a program which was processed by other persons without any errors. That was one of the reasons I decided to update...</p>
  
  <p>I feel like I'm going crazy and don't know what to do. Any constructive idea is much appreciated.</p>