MacLochlainns Weblog

I’ve started building the new image for the database courses. This one needs to include Oracle, MySQL, Cassandra, Hive, and MongoDB databases; and include examples for C, C++, Java, Perl, PHP, Python, R programming languages.

Installing R was a surprise when I saw how many packages there are for it. It’s a standard yum command from the repository, but it will install 256 packages. The command is:

yum install -y R

Once you install it, you simply start the R interpreter, which is part of the Comprehensive R Archive Network (CRAN). Any installation of the R packages includes CRAN, but there are many additional libraries that you may install.

You can launch the R interpreter by typing the following at the Linux command-line:

R

It will display the following licensing information and then the command prompt:

R version 3.2.0 (2015-04-16) -- "Full of Ingredients"
Copyright (C) 2015 The R Foundation for Statistical Computing
Platform: x86_64-redhat-linux-gnu (64-bit)
 
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
 
  Natural language support but running in an English locale
 
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
 
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

You have two options for help. As qualified above, you can type help() to get a Linux man page, and q at the colon quits the man page. Typing help.start() launches a browser interface (shown below), which is more helpful.

You can discover your installed R packages with a call to the installed.packages() function but the output lacks clarity and is verbose. You can see a formatted summary of your installed packages with the following command:

print(as.data.frame(installed.packages()[,c(1,3:4)]),row.names=FALSE)

It should display the following:

    Package Version    Priority
       base   3.2.0        base
       boot  1.3-16 recommended
      class  7.3-12 recommended
    cluster   2.0.1 recommended
  codetools  0.2-11 recommended
   compiler   3.2.0        base
   datasets   3.2.0        base
    foreign  0.8-63 recommended
   graphics   3.2.0        base
  grDevices   3.2.0        base
       grid   3.2.0        base
 KernSmooth 2.23-14 recommended
    lattice 0.20-31 recommended
       MASS  7.3-40 recommended
     Matrix   1.2-0 recommended
    methods   3.2.0        base
       mgcv   1.8-6 recommended
       nlme 3.1-120 recommended
       nnet   7.3-9 recommended
   parallel   3.2.0        base
      rpart   4.1-9 recommended
    spatial   7.3-9 recommended
    splines   3.2.0        base
      stats   3.2.0        base
     stats4   3.2.0        base
   survival  2.38-1 recommended
      tcltk   3.2.0        base
      tools   3.2.0        base
      utils   3.2.0        base

The print() function allows us to remove the text-based indexes from display. The indexes would be the same as the package names. If you call frame() function with a second argument of row.names=FALSE, then R converts the text-based indexes to numeric indexes.

You can quit the R environment with the q() or quit() function calls. It will prompt you whether or not you want to save your workspace before you exit.

It’s time to play with R now. I hope this helps you get started by installing and playing with the R programming language.