Run an action. The actions are searched first in the environment variable GLAYACTIONPATH, then in the built-in action path. These action directories are searched recursively (which means that one cannot use two different actions of the same name). The actions can have an optional .pm extension. opt_args are optional arguments of the specific action.

Input a file. It is simply a shortcut for -a input filename optional_format. The valid file formats are discussed later. If filename is -, then the file is read from the standard output. If the format argument is omitted, glay tries to use the extension of the filename as a format name. If the extension is not a valid format, it falls back to "native".

Dump the graph and related data to a file. It is simply a shortcut for -a dump filename optional_format. The valid file formats are discussed later. If filename is -, then the file is dumped to the standard output. If an optional_format is not given, glay tries to use the extension as a format name. If the extension is not a valid format name, then it falls back to "native".

Read a parameter file. Parameter files are used by some specific actions, for exapmle layout algorithms. The file read by the -p argument is kept in memory, and used later if a corresponding action requires it. Hence one needs to place for example -p J.my_params ahead of the corresponding -a layout J arguments.

Its value can be any colorname found in the file rgb.txt of the current X11 disribution. You can use the xcolors program to select one of them visually, or if you do not have it, you can see the file rgb.txt by saying

glay -a showrgbtxt | less

You can also use RGB colors in hexadecimal format as for example "color=#a312ff", or in a shorter form of "color=#a1f". Further you can use decimal numbers for R, G and B in between 0 and 255 as "color=123,0,12".

The width in case of an edge and the diameter in case of a vertex. A lot of rescaling is going on through the visualization process, so these are really just relative values. It worth to try values between 0.1 and 1, and adjust as needed.

For vertices it can be any of sphere, ball, cube, pyramid, tetrahedron (ball is equivalent with sphere and pyramid is equivalent with tetrahedron). For edges the value of shape must be one of line, cylinder, box, cube. The defaults are ball and cylinder.

It is required by the visualization module that the xyz tag of all vertices should be filled in appropriately with the values of the three dimensional coordinate vectors of the points. You can either choose to have itt filled automatically by a layout algorithm, or fill it manually. See the following two sections on this topic.

A very fast algorithm using integer arithmetic and very simple rules. The quality of the result varies, it worth to try. It is developed by Ingo Bruss and Arne Frick, (Fakultät für Informatik, Universität Karlsruhe). Their actual code has been used while applying just some technical modifications.

An algorithm built from scratch utilizing some bright ideas of Gem, although quality and reusablility (hence variability) were considered as the most important goals, not speed. It is the main and best-tested algorithm we use. It has beed first implemented by Johanna Becker, later reworked by Baldvin Kovács.

JX stands for "J eXtended", and has two important goals: First, demonstrating the possibility (and maybe the ease) of the extension of the J algorithm. Second, to implement something useful. That useful extra knowledge of JX is that one is able to constrain the coordinates of specific points to affin subspaces. In human words it means that one can constrain the positions of the points to planes or lines in the 3 dimensional space, specifying the particular plane or line point-by-point. See Chapter 3 for deatails on how to do it. There is no other difference between JX and J, so you can use J if you don't need this particular extra functionality.

vtx "label", "xyz=[3, 1.6, 12]", ...;

vtx label xyz=3,1.6,12 ...;

Note that there are no spaces between the numbers, since spaces are the separators in this format.

There is no way to specify coordinates for the points using this format.

Here is a snippet from a "native" file showing how the xyz information appears in it:

         'V2' => {
                   'color' => 'brown',
                   'weight' => '1.4',
                   'neighbour' => {
                                    'V4' => 'E3',
                                    'V3' => 'E2',
                                    'V1' => 'E1'
                                  },
                   'xyz' => [
                              '4.7',
                              3,
                              7
                            ]
                 }