littler Project

littler is a command line UNIX program that provides hash-bang (#!) capability for the R Project.

Latest Release

Source: littler-0.1.1.tar.gz [MD5]

Why

GNU R, a language and environment for statistical computing and graphics, provides a wonderful system for 'programming with data' as well as interactive exploratory analysis, often involving graphs.

Sometimes, however, simple scripts are desired. While GNU R can be used in batch mode, and while so-called 'here' documents can be crafted, a long-standing need for a scripting front-end has often been expressed by the R Community.

littler (pronounced 'little R' and written 'r') aims to fill this need.

It can be used directly on the command-line just like, say, bc(1):

        $ echo 'cat(pi^2,"\n")' | r
        9.869604
Equivalently, commands that are to be evaluated can be given on the command-line:

        $ r -e 'cat(pi^2, "\n")'
        9.869604
But unlike bc(1), GNU R has a vast number of statistical functions. For example, we can quickly compute a summary() and show a stem-and-leaf plot for file sizes in a given directory via:
        $ ls -l /boot | awk '!/^total/ {print $5}' | \
             r -e 'fsizes <- as.integer(readLines());
                print(summary(fsizes)); stem(fsizes)'
           Min. 1st Qu.  Median    Mean 3rd Qu.    Max.
             13     512  110100  486900  768400 4735000
        Loading required package: grDevices

          The decimal point is 6 digit(s) to the right of the |

          0 | 00000000000000000011112223
          0 | 5557778899
          1 | 112233
          1 | 5
          2 |
          2 |
          3 |
          3 |
          4 |
          4 | 7

And, last but not least, this (somewhat unwieldy) expression can be stored in a helper script:
        $ cat examples/fsizes.r
        #!/usr/bin/env r

        fsizes <- as.integer(readLines())
        print(summary(fsizes))
        stem(fsizes)
(where calling /usr/bin/env is a trick from Python which allows one to forget whether r is installed in /usr/bin/r, /usr/local/bin/r, ~/bin/r, ...)

A few examples are provided in the source directories examples/ and tests/.

Where

littler can be downloaded from this page (see above), Dirk Eddelbuettel's site, accessed via subversion using the following command:
         $ svn checkout http://littler.googlecode.com/svn/trunk/ littler

or soon be gotten from Debian mirrors via:
         $ apt-get install littler

Who

Copyright (C) 2006 Jeffrey Horner and Dirk Eddelbuettel

littler is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Comments are welcome, as are are suggestions, bug fixes, or patches.

Topic revision: r13 - 27 Aug 2008, JeffreyHorner
 

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