Rpackage.org

Table of Contents

Org-babel support for building R packages

Document Purpose

This document contains

  • tools useful for writing R extensions called packages
  • source code to create a simple R package.

R packages

  • The R language and environment for statistical computation and graphics has a powerful system for developing and distributing software enhancements and datasets called packages.
  • A vast archive of such packages —called CRAN — is available.
  • Users can create their own packages by following instructions in Writing R Extensions.

Some notes on this document and org-babel

  • This document provides tools for R package development using org-mode.
  • There are two somewhat contrary philosophies about how R packages are managed using org-babel.
    • One camp holds that all of the code for a package should be kept in one master *.org document, which when tangled produces the source directory files needed. The .org document also holds notes, utility functions, navigation tools, and code snippets. A very simple R package is included below, and it can be checked, installed, and run from this .org document.
    • The other camp leaves the R and Rd code and other package files in the package directory subfolders and edits them there.
    • The tools shown here support either approach.
  • Some introductory tips at ob-doc-R show how to enable full editing support for R code with ESS (http://ess.r-project.org/).
  • This document is to be put in the top level source directory of an R package (i.e. at the same level as the DESCRIPTION file). To try it out using the built in package, create a fresh diretory named countRows and just put it there.
  • version control blocks here use svn calls, and you may need to replace these with your own.
  • #+begin_src sh ... #+end_src shell blocks work on systems that support unix-like shells. On Windows systems these blocks would likely need to be changed.

Typical Workflow

  • Download the .org version of this document
  • Create a package directory (naming it like the package is convenient)
    • Copy the .org version of this document into that directory
    • Move point to the set up .Rbuildignore headline and execute it (see 1)
    • Create some package files, or create src blocks as outlined in this document and run org-babel-tangle to create the package files.
    • Repeat these steps:
      • Either
        • INSTALL the package1 or
        • check the package1
        • Load some code (i.e. for a function) using ESS and try it out.
        • Inspect a formatted help page
      • Edit the code. Re-tangle as, and if, needed.
    • Once the package is ready, build it or INSTALL it to a permanent location
1. moving point to the corresponding headline, then
   typing 'C-c C-v C-s y' or 
   'M-x org-babel-execute-subtree'
   will execute each tool.

R procedures

check package

  • Environment variables like these may be added in the next src block:
    • export R_LIBS=Rlib
    • export R_ARCH=x86_64
#+begin_src sh :results output
CWD=`pwd`
cd ..; R CMD check $CWD | sed 's/^*/ */'
#+end_src

INSTALL package

  • customize the rckopts variable, possibly "rckopts="
  • Variables may be also added next src block – export R_ARCH=x86_64
#+begin_src sh :results output :var rckopts="--library=./Rlib"
CWD=`pwd`
cd ..; R CMD INSTALL $rckopts $CWD
#+end_src

build package

#+begin_src sh :results output
CWD=`pwd`
cd ..; R CMD build $CWD
#+end_src

help pages

  • The src block adds enough asterisks to the line listing each filename to turn it into a headline at the next level down. This is helpful if you have a lot of help pages and want to fold them up for browsing.
#+begin_src R :results output :var hdlev=(car (org-heading-components))
  linestart <- paste( c( "\n", rep('*', hdlev+1 ) ), collapse='')
  rd.files <- Sys.glob("man/*.Rd")
  for ( ird in rd.files ){
    hlp.txt <- capture.output(tools:::Rd2txt( ird ) )
    hlp.txt <- gsub( "_\b","", hlp.txt)
    headline <- paste( linestart, ird ,'\n' )
    cat( headline, hlp.txt , sep='\n')
  }
#+end_src

load library

  • this loads the library into an R session
  • customize or delete the .libPaths line as desired
#+begin_src R :session :var libname=(file-name-directory buffer-file-name)
.libPaths(new = file.path(getwd(),"Rlib") )
require( basename(libname), character.only=TRUE)
#+end_src

grep require(

  • if you keep all your source code in this .org document, then you do not need to do this - instead just type C-s require(
  • list package dependencies that might need to be dealt with
#+begin_src sh :results output
grep 'require(' R/*
#+end_src

set up .Rbuildignore and man, R, and Rlib directories

  • This document sits in the top level source directory. So, ignore it and its offspring when checking, installing and building.
  • List all files to ignore under #+results: rbi (including this one!). Regular expressions are allowed.
  • Rlib is optional. If you want to INSTALL in the system directory, you won't need it.
#+results: rbi
Rpackage.*

Only need to run this once (unless you add more ignorable files).

#+begin_src R :results output silent :var rbld=rbi 
cat(rbld,'\n', file=".Rbuildignore")
dir.create("man")
dir.create("R")
dir.create("../Rlib")
#+end_src

Project Specific Entries

Package specific notes and blocks go here. It is a good idea to have several second level headlines — possibly including the package code — to group things by topic/idea, then a third level headline for almost every src block and TODO item.

Example: The countRows package

  • This example illustrates how to use the .org document as the source code master. By navigating to the INSTALL package headline and entering C-c C-v C-s y, the INSTALL command is run. Likewise for check package, help pages, and the other tools.
  • The countRows package implements a simple, but quick way to count the rows of a data.frame. It is akin to sort | uniq -c in a Unix-alike shell.
  • The package is based on a function that was posted in this reply to a query on the R-help list.

The DESCRIPTION File

  • The DESCRIPTION file is obligatory
  • It follows Debian Control File format.
  • Required and optional fields are described in Writing R Extensions.
#+begin_src sh :results silent :tangle DESCRIPTION :eval nil
Package: countRows
Type: Package
Title: Count Rows of a data.frame
Version: 1.0
Date: 2010-12-08
Author: Charles C. Berry
Maintainer: Charles Berry <cberry@tajo.ucsd.edu>
Description: One of many ways to count the rows of a data.frame. 
        Akin to 'sort | uniq -c' shell command
License: GPL-3
LazyLoad: yes
#+end_src 

R code

  • Each #+begin_src R block defines one or more functions.
  • The :tangle header tells where to place the code
  • count.rows function
    #+begin_src R :eval nil :exports code :tangle R/count.rows.R  
      count.rows <-
        function( x )
        {
          order.x <- do.call( order, as.data.frame(x) )
          equal.to.previous <-
            rowSums( x[tail(order.x,-1),] != x[head(order.x,-1),] )==0
           tf.runs <- rle(equal.to.previous)
           counts <- c(1,
                       unlist(mapply( function(x,y) if (y) x+1 else (rep(1,x)),
                                     tf.runs$length, tf.runs$value )))
           counts <- counts[ c( diff( counts ) <= 0, TRUE ) ]
           unique.rows <- which( c(TRUE, !equal.to.previous ) )
           cbind( counts, x[ order.x[ unique.rows ], ,drop=FALSE ] )
         }
    #+end_src 
    

Rd help page markup

  • There is usually one #+begin_src Rd block for each help page
  • Usually one page covers the package as a whole and other cover the functions and datasets it includes.
  • count.rows
    #+begin_src Rd :eval nil :tangle man/count.rows.Rd
      \name{count.rows}
      \alias{count.rows}
      \title{ Count \code{data.frame} rows }
      \description{ Counts the unique rows of a \code{data.frame} }
      \usage{ count.rows(x) }
      \arguments{
        \item{x}{
          Just a \code{data.frame} or \code{matrix}
        }
      }
      \details{
        Basically, this function tries to be smart about counting
        rows. It relies on the \code{\link{order}} function and basic logic to
        do the heavy lifting.  
      }
      \value{
        A \code{data.frame} with a column named \code{counts}, all the olumns
        of \code{x} and the rows that would appear in \code{unique( x )}. 
      }
      \author{
        Charles C. Berry \email{ccberry@ucsd.tajo.edu }
      }
      \examples{
      hec.frame <- as.data.frame( HairEyeColor )
      hec.frame <-
        hec.frame[ rep(1:nrow(hec.frame), hec.frame$Freq ), ]
      hec.counts <- count.rows( hec.frame )
      all.equal( hec.counts$counts, hec.counts$Freq )
      hec.counts
      
      }
       \keyword{ manip }
    #+end_src 
    
  • countRows-package
    #+begin_src Rd :eval nil :tangle man/countRows-package.Rd
      \name{countRows-package}
      \alias{countRows-package}
      \alias{countRows}
      \docType{package}
      \title{Count \code{data.frame} rows }
      \description{  Counts the unique rows of a \code{data.frame} }
      \details{
      \tabular{ll}{
      Package: \tab countRows\cr
      Type: \tab Package\cr
      Version: \tab 1.0\cr
      Date: \tab 2010-12-08\cr
      License: \tab GPL-3\cr
      LazyLoad: \tab yes\cr
      }
      
      There is only one function in this package, \code{count.rows} and it
      does what it says.
      }
      \author{
      Charles C. Berry \email{cberry@ucsd.tajo.edu}
      }
      \keyword{ package }
    #+end_src 
    

Tests and Tryouts

  • As part of developing a package one must try out some code and perhaps develop some tests to be sure it does what it is supposed to do.
  • Here is an easy-to-read tryout of the count.rows function:
  • You may need to edit or delete the .libPaths call to suit your setup
#+begin_src R :session :results output :exports both
 .libPaths( new = "./Rlib")
  require( countRows ) 
  simple.df <- data.frame( diag(1:4), row.names=letters[ 1:4 ])
  repeated.df <- simple.df[ rep( 1:4, 4:1 ), ]
  simple.df
  count.rows( repeated.df )  
#+end_src
Loading required package: countRows
  X1 X2 X3 X4
a  1  0  0  0
b  0  2  0  0
c  0  0  3  0
d  0  0  0  4
  counts X1 X2 X3 X4
d      1  0  0  0  4
c      2  0  0  3  0
b      3  0  2  0  0
a      4  1  0  0  0

Version Control, Navigation, and setup tasks

list files for convenient navigation

  • Use this if you do not use the .org document to keep the master for the source code
  • It is useful when in a terminal window on a remote machine, and speedbar is not a good option. C-u C-c C-o or Mouse-1 will open the file point is on.
#+begin_src R :results output verbatim :var cwd="."
  cat(paste("file:",list.files(cwd,".*",recursive=TRUE),sep=''),sep='\n')
#+end_src

Speedbar navigation

  • Use this if you do not use the .org document to keep the master for the source code
  • Make speedbar stick to the package source directory by typing 't' in its frame after executing this block:
#+begin_src emacs-lisp :results output silent
  (require 'speedbar)
  (ess-S-initialize-speedbar)
  ;; uncomment this line if it isn't in ~/.emacs:
  ;; (add-to-list 'auto-mode-alist '("\\.Rd\\'" . Rd-mode))
  (speedbar-add-supported-extension ".Rd")
  (speedbar-add-supported-extension "NAMESPACE")
  (speedbar-add-supported-extension "DESCRIPTION")
  (speedbar 1)
#+end_src

Version Control

  • If you don't use svn, substitute the relevant version control command in each block in this section
  • Each of these can be run by putting point on the headline then keying C-c C-v C-s y
  • Possibly add –username=<> –password=<> to the svn commands

svn list

  • Show what files are version controlled
#+begin_src sh :results output
svn list --recursive 
#+end_src

svn update

  • Use at the start of each session to sync changes from other machines
#+begin_src sh :results output
svn update 
#+end_src

svn commit

  • At the end of a day's work commit the changes
#+begin_src sh :results output
svn commit  -m "edits"
#+end_src

Documentation from the http://orgmode.org/worg/ website (either in its HTML format or in its Org format) is licensed under the GNU Free Documentation License version 1.3 or later. The code examples and css stylesheets are licensed under the GNU General Public License v3 or later.