NAME
dijkstra - single-source distance filter
SYNOPSIS
dijkstra [ -a? ] [ sourcenode
file ]
DESCRIPTION
dijkstra reads a stream of graphs and
for each computes the distance of every node from
sourcenode. Edge length is given in the len
attribute, and the default is 1. The dist attribute of every
node is set to its distance from sourcenode. The graph
attribute maxdist is set to the maximum dist of all
nodes in the graph. By default, if the graph is disconnected, the
dist attribute of nodes unreachable from sourcenode
are left untouched, and maxdist is set to the maximum of any
previous value and the largest distance recorded in this run. On
the other hand, if the -a flag is used, the dist
attribute of an unreachable node is assigned a very large value,
and maxdist records the maximum distance found in the
component containing sourcenode. Any number of sourcenode
file pairs may be given. If the last file is missing,
stdin is used. All output is written to stdout. In a
typical application, dist and maxdist can drive a
downstream calculation of color or some other attribute.
SEE ALSO
gvpr(1),
gvcolor(1),
libgraph(3)