Gri is a programming language for scientific graphics. It can make x-y graphs, contour-graphs, and image graphs. In addition, Gri has a full suite of low-level graphical elements and sufficient programming capabilities (loops, subroutines, etc) to permit complex customization.
Gri is not point-click. In some ways it is analogous to TeX. Extensive power rewards tolerance of a modest learning curve.
If a command file (CommandFile) is named, commands are read from that file; otherwise they are read from the keyboard. If a command file is named, then a file in which to store the PostScript output may also be named; otherwise it is stored in a file named by substituting the .ps extension instead of .gri in CommandFile. If no command file is named, the output is named gri-00.ps (or gri-01.ps if gri-00.ps exists, etc).
There are 3 special forms that do no graphing:
`gri -creator postscript_file'
`gri -help' or `gri -h'
`gri -version' or `gri -v'
In normal usage, where drawing is expected, Gri takes these options:
-batch or -b
2: print cmdline before/after substituting rpn expressions
4: print new commands being defined
8: print system commands and `open "... | "' commands before
256: for author's use only
For more information, please consult online info and html manuals.
The info manual included in the main gri Debian package is normally accessed by typing
(or from within Emacs' own info).
There are also reference cards in postscript format. See /usr/share/doc/gri/*refcard.ps
The Debian package gri-html-doc provides the html manual, which when installed is then located at
or, if you have a web server installed, at
The HTML manual is accessible via dwww and dhelp Debian help interfaces. The html FAQ is located at
The gri-html-doc package also includes examples in /usr/share/doc/gri/examples/ which are described in the manual, and are included as a quick start primer.
The gri-ps-doc package is a PostScript version of the manual suitable for printing.
Two Perl scripts are provided with Gri to manipulate the PostScript output.
gri_merge is used to merge multiple Gri output files into a single PostScript file. See gri_merge -h and its man page for usage information.
gri_unpage is used is split a multi-page Gri output file (in which the new page command was used) into separate PostScript files, one for each page.
See their respective man pages.
An emacs mode is provided with Gri. It is documented in the gri Info or HTML manual.
The mode is installed automatically in Debian by the elisp file:
The emacs mode itself is gri-mode.el and is installed on Debian as /usr/share/emacs/site-lisp/gri-mode.el
Byte-compiled versions of this file are produced for every flavour of Emacs that is installed, and are located in places like /usr/share/emacs/23.1/site-lisp/gri-el/gri-mode.elc
This manual page by Peter S Galbraith <email@example.com>.