NAME¶

tred - transitive reduction filter for directed graphs

SYNOPSIS¶

tred [ -vr? ] [ files ]

DESCRIPTION¶

tred computes the transitive reduction of directed graphs, and prints the resulting graphs to standard output. This removes edges implied by transitivity. Nodes and subgraphs are not otherwise affected. The ``meaning'' and validity of the reduced graphs is application dependent. tred is particularly useful as a preprocessor to dot to reduce clutter in dense layouts.

Undirected graphs are silently ignored.

OPTIONS¶

The following options are supported:

-v

Verbose output to stderr.

-r

Print information of removed edges to stderr.

-?

Print usage information.

OPERANDS¶

The following operand is supported:

files

Names of files containing 1 or more graphs in dot format. If no files operand is specified, the standard input will be used.

BUGS¶

Using bitmaps internally would substantially decrease running time.

DIAGNOSTICS¶

If a graph has cycles, its transitive reduction is not uniquely defined. In this case tred emits a warning.

AUTHORS¶

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

SEE ALSO¶

gc(1), dot(1), acyclic(1), gvpr(1), gvcolor(1), ccomps(1), sccmap(1), libgraph(3)