gvcolor - flow colors through a ranked digraph
( previously known as colorize )
gvcolor [ files ]
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 colors 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
necessarily spaced evenly around the color wheel. For example,
blue_green, green, and light_yellow 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 <email@example.com>
Emden R. Gansner <firstname.lastname@example.org>
gc(1), dot(1), gvpr(1), ccomps(1), sccmap(1), tred(1), libgraph(3)
21 March 2001