Using R with Emacs and ESS

apt-get install emacs ess r-recommended 

Prepackaged versions are often old. To get features from the newest releases you need to install from source.

#!/bin/bash
set -o errexit
cd ~/R
if [ -f R-devel.tar.gz ];then 
    rm R-devel.tar.gz
fi
wget ftp://ftp.stat.math.ethz.ch/Software/R/R-devel.tar.gz
if [ -d R-devel ];then
    rm -r R-devel
fi
tar xf R-devel.tar.gz
cd R-devel
./configure --prefix=$HOME --with-cairo
make
make install

This is the startup file that is read whenever R starts up on your system without the –vanilla option. There are a few essential things that you should put inside.

## This avoids having to interactively select the mirror
## during each R session.
## Change to reflect the closest CRAN mirror to you.
options(repos=c("http://cran.univ-lyon1.fr/","http://cran.r-project.org"))
if(interactive()){
  ## Open a new cairo device in the bottom right.
  ## This avoids having to move/resize the plot window for each session.
  require(grDevices)
  X11.options(type="cairo")
  x11(xpos=-1,ypos=-1)
}

This is the file read each time Emacs starts up. Below I have just included parts that are relevant to using R with ESS.

;; ESS mode configuration (only if ess is in a nonstandard place)
(add-to-list 'load-path "/path/to/ess-5.3.4/lisp");;<<CHANGE
(autoload 'R-mode "ess-site.el" "ESS" t)
(add-to-list 'auto-mode-alist '("\\.R$" . R-mode))
(setq inferior-R-program-name "/path/to/R");;<<CHANGE
;;R stuff
(setq ess-eval-visibly-p nil)
(setq ess-ask-for-ess-directory nil)
(require 'ess-eldoc)
;;compile the first target in the Makefile in the current directory using F9
(global-set-key [f9] 'compile)
(setq compilation-read-command nil)
;;show matching parentheses
(show-paren-mode 1)

M-x compile, bound as F9 in .emacs allows 1-touch recompilation. Often I work on C/C++ code in some file prog.c with the intent to interface it with R/Python. For testing purposes it is easiest to make some simple testing code in main.c then make a Makefile:

prog.out: prog prog.in
        ./prog prog.in|tee prog.out
prog: prog.c main.c
        gcc -Wall prog.c main.c -o prog

Then when you hit F9 in emacs, it will run make in a new compilation buffer, and you will see errors and warnings from the compiler in this buffer. Hit tab to skip between them and enter to jump to the position in the code where it occured.

If you have several programs in the same makefile, you can declare a custom command line for a particular file at the top of your other.c:

/* -*- compile-command: "make other.out"; some-other-var: nil -*- */ 

Run a grep like from the shell, but better for 2 reasons: can isearch through the results in emacs, and can hit enter to jump to the line where something was found. Also check out http://www.emacswiki.org/emacs/Icicles

This is awesome. It gives you instant interactive visual feedback for constructing regular expressions. First C-x C-f find the file where you will be applying your regexp. Then do M-x regexp-builder. Then type your regexp between the quotes in the little window that appears, and all the matches in the original buffer will be highlighted in blue.

This allows many things, but I use it mainly to quickly write up webpages from emacs. Get it from http://orgmode.org/ and make sure you have http://www.emacswiki.org/emacs/Htmlize for syntax highlighting of code in #+BEGIN_SRC mode code #+END_SRC. To insert one of these blocks, go to a new line and insert <s then type tab.

Use C-c C-e b to convert the current buffer to HTML and preview in a browser.

Use C-c C-l to insert a link, or C-u C-c C-l to insert a link to a local file.