gvcolor - flow colors through a ranked digraph
( previously known as colorize )
gvcolor [ files ]
dot file.gv | gvcolor | dot -T<format>
gvcolor is a filter that sets node colors from initial seed values. Colors flow along
edges from tail to head, and are averaged (as HSB vectors) at nodes. The graph must
already have been processed by dot. Appropriate choice of initial colors yields drawings
in which node colors help to emphasize logical relationships between nodes, even when they
are spread far apart in the layout.
Initial colors must be set externally, using the color attribute of a node. It is often
effective to assign colors to a few key source or sink nodes, manually setting their col-
ors by editing the graph file. Color names are as in dot(1): symbolic names or RGB
triples. It is best to choose some easily-distinguished but related colors; not necessar-
ily spaced evenly around the color wheel. For example, blue_green, green, and light_yel-
low looks better than red, green, blue.
Certain graph attributes control the gvcolor algorithm. flow=back reverses the flow of
colors from heads to tails. saturation=.1,.9 (or any two numbers between 0 and 1) adjusts
the color saturation linearly from least to greatest rank. If Defcolor is set, this color
value is applied to any node not otherwise colored.
The following exit values are returned:
0 Successful completion.
1 If nodes of the graph do not possess a ``pos'' attribute.
It would be nice to make the program work without relying on an initial pass through dot.
Stephen C. North <firstname.lastname@example.org>
Emden R. Gansner <email@example.com>
gc(1), dot(1), gvpr(1), ccomps(1), sccmap(1), tred(1), libgraph(3)
21 March 2001 GVCOLOR(1)