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 use GNU Emacs 28 or above, and Gnuplot version 5.0 or above.

Installation

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

M-x install-package RET gnuplot RET

or do M-x list-packages and search for gnuplot in the list. Note that there is a different gnuplot-mode package on MELPA which is less featureful.

Configuration

In order to customize Gnuplot, use M-x gnuplot-customize or set the respective customizable variables in your user configuration.

It is recommended to configure read-extended-command-predicate in your Emacs configuration, such that M-x only completes commands relevant for the current mode. For example gnuplot-* commands are only shown in Gnuplot buffers. Alternatively press the key M-X instead of M-x if you want relevant commands only.

(setq read-extended-command-predicate #'command-completion-default-include-p)

Usage

gnuplot-mode is enabled automatically for *.gp files. These functions are useful as entry points:

• M-x run-gnuplot - start gnuplot-comint-mode REPL.
• M-x gnuplot-mode - switch to 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 manual
C-c C-e	show gnuplot buffer
C-c C-k	kill gnuplot process
C-c C-z	customize gnuplot-mode
M-TAB	complete keyword before point
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 manual.

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

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 outdated version of gnuplot it will make mistakes. Most of gnuplot 4.6’s command language is parsed correctly except for the set terminal commands.

Eldoc mode

gnuplot-mode shows syntax hints in the modeline when eldoc-mode is turned on and context sensitivity is enabled. Both are enabled by default.

Inline Images

Plots are 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. It requires Gnuplot and Emacs to have png support. Call gnuplot-external-display-mode in a gnuplot-mode buffer to disable the feature.

Common issues

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). More information on gnuplot.el and Windows can be found on these threads 1 and 2. You currently have two solutions:

1. Experiment using the gnuplot-program and gnuplot-program-args variables. For instance the following setting has been reported to work (see here).

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

2. Try 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 this package.

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 fixes the issue until this issue is fixed upstream.

Maintenance of generated files

The files gnuplot.texi and gnuplot-eldoc.el are generated from the Gnuplot source, which can be obtained from https://packages.debian.org/unstable/gnuplot. Run make inside the admin directory to download the source and regenerate the files.