gnuplot

gnuplot
	3D rendering of an ellipsoid by gnuplot
Initial release	1986
Stable release	5.2.4 (June 4, 2018) [±]
Preview release	5.3 [±]
Repository	https://git.code.sf.net/p/gnuplot/gnuplot-main;
Written in	C
Type	Plotting
License	Gnuplot license (rights to distribute modified versions are withheld)[1]
Website	gnuplot.info

gnuplot is a command-line program that can generate two- and three-dimensional plots of functions, data, and data fits. It is frequently used for publication-quality graphics as well as in education. The program runs on all major computers and operating systems (Linux, Unix, Microsoft Windows, macOS, and others). It is a program with a fairly long history, dating back to 1986. Despite its name, this software is not part of the GNU project.

Features

gnuplot can produce output directly on screen, or in many formats of graphics files, including Portable Network Graphics (PNG), Encapsulated PostScript (EPS), Scalable Vector Graphics (SVG), JPEG and many others. It is also capable of producing LaTeX code that can be included directly in LaTeX documents, making use of LaTeX's fonts and powerful formula notation abilities. The program can be used both interactively and in batch mode using scripts.

The program is well supported and documented. Extensive help can also be found on the Internet.^[2]^[3]

The gnuplot core code is programmed in C. Modular subsystems for output via Qt, wxWidgets, and LaTeX/TikZ/ConTeXt are written in C++ and Lua.

gnuplot in interactive use.

The code below creates the graph to the right.

set title "Some Math Functions"
set xrange [-10:10]
set yrange [-2:2]
set zeroaxis
plot (x/4)**2, sin(x), 1/x

A scatter plot of samples from a text file.

Thousands of dots plotted, forming a pattern

A logarithmic spiral.

The name of this program was originally chosen to avoid conflicts with a program called "newplot", and was originally a compromise between "llamaplot" and "nplot".^[4]

Distribution terms

Despite gnuplot's name, it is not named after, part of or related to the GNU Project, nor does it use the GNU General Public License. It was named as part of a compromise by the original authors, punning on gnu (the animal) and newplot.^[5]

Official source code to gnuplot is freely redistributable, but modified versions thereof are not. The gnuplot license instead recommends distribution of patches against official releases, optionally accompanied by officially released source code. Binaries may be distributed along with the unmodified source code and any patches applied thereto. Contact information must be supplied with derived works for technical support for the modified software.^[1]

Permission to modify the software is granted, but not the right to distribute the complete modified source code. Modifications are to be distributed as patches to the released version.

Despite this restriction, gnuplot is accepted and used by many GNU packages and is widely included in Linux distributions including the stricter ones such as Debian and Fedora. The OSI Open Source Definition and the Debian Free Software Guidelines specifically allow for restrictions on distribution of modified source code, given explicit permission to distribute both patches and source code.

Newer gnuplot modules (e.g. Qt, wxWidgets, and cairo drivers) have been contributed under dual-licensing terms, e.g. gnuplot + BSD or gnuplot + GPL.

GUIs and programs that use gnuplot

Several third-party programs have graphical user interfaces that can be used to generate graphs using gnuplot as the plotting engine. These include:

gretl, a statistics package for econometrics
JGNUPlot, a java-based GUI^[6]
Kayali^[7] a computer algebra system
xldlas, an old X11 statistics package^[8]
gnuplotxyz, an old Windows program^[9]
wxPinter, a graphical plot manager for gnuplot^[10]
Maxima is a text-based computer algebra system which itself has several third-party GUIs.

Other programs that use gnuplot include:

GNU Octave, a mathematical programming language
statist, a terminal-based program^[11]
gplot.pl provides a simpler command-line interface.^[12]
feedgnuplot provides a plotting of stored and realtime data from a pipe.
ElchemeaAnalytical,^[13] an Impedance spectroscopy plotting and fitting program developed by DTU Energy^[14]
Gnuplot add-in for MS-Excel

Programming and application interfaces

gnuplot can be used from various programming languages to graph data, including Perl (via PDL and other CPAN packages), Python (via Gnuplot-py and SageMath), Julia (via Gaston.jl), Java (via JavaGnuplotHybrid and jgnuplot), Ruby (via Ruby Gnuplot), Ch (via Ch Gnuplot), Haskell (via Haskell gnuplot), Fortran 95,^[15] and Smalltalk (Squeak and GNU Smalltalk).

gnuplot also supports piping, which is typical of scripts.^[16] For script-driven graphics, gnuplot is by far the most popular program.

References

1 2 "gnuplot licence".
↑ Gnuplot manual (PDF), retrieved 2018-05-15
↑ How to generate graphs with gnuplot, retrieved 2012-07-19
↑ Gnuplot FAQ
↑ "1.2 How did it come about and why is it called gnuplot?". gnuplot. Retrieved 2015-02-21.
↑ http://jgp.sourceforge.net/
↑ http://kayali.sourceforge.net/index.htm
↑ "{title}". Archived from the original on 2014-10-31. Retrieved 2014-10-30.
↑ http://www.uni-hamburg.de/Wiss/FB/15/Sustainability/schneider/gnuplot/
↑ Steingrube, Daniel S. "Steingrube". www.steingrube-home.de. Retrieved 2015-08-21.
↑ http://wald.intevation.org/projects/statist/
↑ http://gplot.sourceforge.net/
↑ https://www.elchemea.com/
↑ http://www.energy.dtu.dk/english
↑ Singh, Madhusudan. "gnuplotfortran - the Fortran 95 interface to gnuplot". gnuplotfortran.sourceforge.net. Retrieved 10 May 2016.
↑ Piping to GNU Plot from C by Amit Saha