org-mode/contrib/babel/library-of-babel.org

174 lines
5.1 KiB
Org Mode

#+title: The Library of Babel
#+author: Org-mode People
#+STARTUP: odd hideblocks
* Introduction
The Library of Babel is an extensible collection of ready-made and
easily-shortcut-callable source-code blocks for handling common
tasks. Org-babel comes pre-populated with the source-code blocks
located in this file. It is possible to add source-code blocks from
any org-mode file to the library by calling =(org-babel-lob-ingest
"path/to/file.org")=.
This file is included in worg mainly less for viewing through the
web interface, and more for contribution through the worg git
repository. If you have code snippets that you think others may
find useful please add them to this file and [[file:~/src/worg/worg-git.org::contribute-to-worg][contribute them]] to
worg.
The raw Org-mode text of this file can be downloaded at
[[repofile:contrib/babel/library-of-babel.org][library-of-babel.org]]
* Simple
A collection of simple utility functions
#+srcname: echo
#+begin_src emacs-lisp :var input="echo'd"
input
#+end_src
* File I/O
** reading and writing files
Read the contents of the file at =path= into a string.
#+srcname: read
#+begin_src emacs-lisp :var path=""
(with-temp-filebuffer path
(buffer-substring (point-min) (point-max)))
#+end_src
Read the lines of the file at =path= into a list.
#+srcname: read-lines
#+begin_src emacs-lisp :var path=""
(split-string
(with-temp-filebuffer path
(buffer-substring (point-min) (point-max))))
#+end_src
Write =data= to a file at =path=. If =data= is a list, then write it
as a table in traditional Org-mode table syntax.
#+srcname: write
#+begin_src emacs-lisp :var data="" :var path=""
(with-temp-file path
(org-babel-insert-result data))
nil
#+end_src
** remote files
Read local or remote file in [[http://www.json.org/][json]] format into emacs-lisp objects.
#+srcname: json
#+begin_src emacs-lisp :var file='() :var url='()
(require 'json)
(cond
(file
(with-temp-filebuffer file
(goto-char (point-min))
(json-read)))
(url
(require 'w3m)
(with-temp-buffer
(w3m-retrieve url)
(goto-char (point-min))
(json-read))))
#+end_src
* Plotting code
** R
Plot column 2 (y axis) against column 1 (x axis). Columns 3 and beyond, if present, are ignored.
#+srcname: R-plot(data=R-plot-example-data)
#+begin_src R :session *R*
plot(data)
#+end_src
#+tblname: R-plot-example-data
| 1 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 16 |
| 5 | 25 |
#+lob: R-plot(data=R-plot-example-data)
#+resname: R-plot(data=R-plot-example-data)
: nil
** Gnuplot
* Tables
** LaTeX Table export
This block can be used to wrap a table in the latex =longtable=
environment, it takes the following arguments -- all but the first two
are optional.
| arg | description |
|-----------+-------------------------------------------------------------|
| table | a reference to the table |
| align | optional alignment string |
| width | optional width specification string |
| hline | the string to use as hline separator, defaults to "\\hline" |
| head | optional "head" string |
| firsthead | optional "firsthead" string |
| foot | optional "foot" string |
| lastfoot | optional "lastfoot" string |
#+srcname: longtable
#+begin_src emacs-lisp :var table='((:table)) :var env="table" :var align='() :var width='() :var hline="\\hline" :var firsthead='() :var head='() :var foot='() :var lastfoot='() :noweb yes :results latex
(org-fill-template
"
\\begin{longtable}%width%align
%firsthead
%head
%foot
%lastfoot
%table
\\end{longtable}\n"
(list
(cons "width" (if width (format "{%s}" width) ""))
(cons "align" (if align (format "{%s}" align) ""))
(cons "firsthead" (if firsthead (concat firsthead "\n\\endfirsthead\n") ""))
(cons "head" (if head (concat head "\n\\endhead\n") ""))
(cons "foot" (if foot (concat foot "\n\\endfoot\n") ""))
(cons "lastfoot" (if lastfoot (concat lastfoot "\n\\endlastfoot\n") ""))
(cons "table" (orgtbl-to-generic
(mapcar (lambda (lis)
(if (listp lis)
(mapcar (lambda (el)
(if (stringp el)
el
(format "%S" el))) lis)
lis)) table)
(list :lend " \\\\" :sep " & " :hline hline)))))
#+end_src
** Elegant lisp for transposing a matrix.
#+tblname: transpose-example
| 1 | 2 | 3 |
| 4 | 5 | 6 |
#+srcname: transpose
#+begin_src emacs-lisp :var table=transpose-example
(apply #'mapcar* #'list table)
#+end_src
#+resname:
| 1 | 4 |
| 2 | 5 |
| 3 | 6 |
* Misc
#+srcname: python-identity(a=1)
#+begin_src python
a
#+end_src
#+srcname: python-add(a=1, b=2)
#+begin_src python
a + b
#+end_src