


TRED(1)                                                   TRED(1)


NAME
       tred - transitive reduction filter for directed graphs

SYNOPSIS
       tred [ 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  depen-
       dent.   tred  is particularly useful as a preprocessor to dot to reduce
       clutter in dense layouts.

       Undirected graphs are silently ignored.

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)





















                          21 March 2001                         1


