Gnuplot for Emacs

This package allows running gnuplot files from within the GNU Emacs editor. It features:

• Syntax highlighting and indentation for gnuplot scripts.
• Pull-down menus for common gnuplot-related tasks.
• Interactive gnuplot sessions using comint.
• Context-sensitive completion.
• Inline display of gnuplot plots.

It is recommended to run gnuplot-mode on GNU Emacs 25 or above, using gnuplot version 5.0 or above.

Installation

Using MELPA

The easiest way to install gnuplot-mode is to directly get it from MELPA. After configuring Emacs to use MELPA, you should be able to install gnuplot-mode by typing

M-x install-package RET gnuplot RET

or do M-x list-packages and search for gnuplot in the list.

Using el-get

The el-get package includes a gnuplot-mode recipe. So to install simply call

M-x el-get-install RET gnuplot-mode

Alternatively, you can directly place the following in your init file so that el-get can install and load gnuplot-mode at Emacs start up:

(el-get 'sync 'gnuplot-mode)

From source

After fetching the package’s source from the homepage, byte-compile the package’s files using the make command and move the compiled .elc files to your chosen target directory.

Configuration

Load Path

First of all, make sure that gnuplot.el is in your load-path (this is automatic if using a package helper like use-package). To do so manually, add the following snippet in your emacs configuration file

(add-to-list 'load-path "/path/to/gnuplot")

Info File

The function gnuplot-info-lookup-symbol looks at the Gnuplot info file. For that function to work, a gnuplot.info file must be placed somewhere where info can find it. The following snippet allows you to put the gnuplot.info any place convenient:

(add-to-list 'Info-default-directory-list "/path/to/info/file")

Enable Mode

You can automatically enable gnuplot-mode using the snippet below:

(autoload 'gnuplot-mode "gnuplot" "Gnuplot major mode" t)
(autoload 'gnuplot-make-buffer "gnuplot" "open a buffer in gnuplot-mode" t)
(setq auto-mode-alist (append '(("\\.gp$" . gnuplot-mode)) auto-mode-alist))

Usage

Apart from enabling gnuplot-mode automatically (see above), these two functions are useful for starting up gnuplot-mode:

• M-x gnuplot-mode : start gnuplot-mode in the current buffer
• M-x gnuplot-make-buffer : open a new buffer (which is not visiting a file) and start gnuplot-mode in that buffer

Bindings

When gnuplot-mode is on, the following keybindings are available:

C-c C-l	send current line to gnuplot
C-c C-v	send current line to gnuplot and move forward 1 line
C-c C-r	send current region to gnuplot
C-c C-b	send entire buffer to gnuplot
C-c C-f	send a file to gnuplot
C-c C-i	insert filename at point
C-c C-n	negate set option on current line
C-c C-c	comment region
C-c C-o	set arguments for command at point
S-mouse-2	set arguments for command under mouse cursor
C-c C-d	read the gnuplot info file
C-c C-e	show-gnuplot-buffer
C-c C-k	kill gnuplot process
C-c C-z	customize gnuplot-mode
M-tab or M-ret	complete keyword before point
ret	newline and indent
tab	indent current line

With the exception of the commands for sending commands to Gnuplot, most of the above commands also work in the Gnuplot comint buffer, in addition to the following:

M-C-p	plot the most recent script buffer line-by-line
M-C-f	save the current script buffer and load that file
C-c C-e	pop back to most recent script buffer

Context-sensitive keyword completion

By default gnuplot-mode will try to parse your commands as you type and suggest only relevant completion candidates on typing M-TAB or TAB. For example, with point after the with of a plot command, tab completion will suggest only plotting styles. This also enables more specific help topic lookup in the gnuplot info file, provided you have the right version of gnuplot.info installed (see the Installation section for isntructions).

If the context-sensitivity annoys you, you can get simple non-context-sensitive completion back by toggling gnuplot-context-sensitive-mode. See also the variable gnuplot-tab-completion.

By its nature, the completion code has to know a fair bit about the structure of the gnuplot language. If you use it with an old version of gnuplot (pre version 4) it will make mistakes. Most of gnuplot 4.6’s command language is parsed correctly except for the set terminal commands.

Eldoc mode

If you install the file gnuplot-eldoc.el from a recent Gnuplot distribution, gnuplot-mode can show syntax hints in the modeline when eldoc-mode is turned on and context sensitivity is enabled.

Inline Images

You can optionally have plots displayed inline in the Gnuplot comint process buffer. This is handy for trying things out without having to switch between Emacs and the Gnuplot display. Call gnuplot-inline-display-mode in a gnuplot-mode buffer to try it out. This feature is implemented using temporary png files, and is also somewhat experimental. It requires Gnuplot to have png support and a GNU Emacs with image support. Please report bugs.

FAQ / Remarks

Usage on Windows

Multiple users have reported issues when trying to work with gnuplot.el on Windows. Most notably, the gnuplot process hangs after sending a first line of input (this is a common Emacs issue on Windows, see here).

A partial workaround was to use pgnuplot.exe as the gnuplot-program. However, pgnuplot.exe is not included with gnuplot since version 5.0.

You currently have two solutions:

1. Experiment using the gnuplot-program and gnuplot-program-args variables. For instance, setting

   (setq gnuplot-program "/path/to/cmdproxy.exe")
   (setq gnuplot-program-args "/C /path/to/gnuplot.exe")
       

   has been reported to work (see here for a reference).

2. Use the simpler gnuplot-mode package that sends the entire buffer to gnuplot. Since no comint is involved, it should function correctly, but you lose most features of the gnuplot.el package. We would like to implement a send-buffer without comint as well eventually.

More information on gnuplot.el and Windows can be found on these threads: 1, 2

Pause Command

Gnuplot’s pause -1 command, which waits for the user to press a key, is problematic when running under Emacs. Sending pause -1 to the running gnuplot process will make Emacs appear to freeze. (It isn’t really crashed: typing C-g will unlock it and let you continue). The workaround for now is to make Gnuplot output a string before pausing, by doing =pause -1 “Hit return”= or similar.

Issue with Unicode Character Display

Some users have reported issues when trying to display unicode characters. This issue is likely due to your distribution bundling gnuplot with editline instead of readline. Recompiling the source with support for unicode should fix the issue until this issue is fixed upstream. Thanks to rolandog for discovering this fix.