GVCOLOR(1)						      General Commands Manual							GVCOLOR(1)

NAME
       gvcolor - flow colors through a ranked digraph
       ( previously known as colorize )

SYNOPSIS
       gvcolor [ files ]

USAGE
       dot file.dot | gvcolor | dot -T<format>

DESCRIPTION
       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.

EXIT STATUS
       The following exit values are returned:

       0   Successful completion.

       1   If nodes of the graph do not possess a ``pos'' attribute.

BUGS
       It would be nice to make the program work without relying on an initial pass through dot.

AUTHORS
       Stephen C. North <north@research.att.com>
       Emden R. Gansner <erg@research.att.com>

SEE ALSO
       gc(1), dot(1), gvpr(1), ccomps(1), sccmap(1), tred(1), libgraph(3)

								   21 March 2001							GVCOLOR(1)