NAME¶
ccomps - connected components filter for graphs
SYNOPSIS¶
ccomps [
-sxvnzC? ] [
-X[#]v ] [
-ooutfile ] [
files ]
DESCRIPTION¶
ccomps decomposes graphs into their connected components, printing the
components to standard output.
OPTIONS¶
The following options are supported:
- -s
- No output graph is printed. The return value can be used to
check if the graph is connected or not.
- -x
- Only the connected components are printed, as separate
graphs.
- -v
- Counts of nodes, edges and connected components are
printed.
- -z
- Sort components by size, with the largest first. This is
only effective if either -x or -X#v is present. Thus,
-zX#0 will cause the largest component to be printed.
- -C
- Use clusters in computing components in addition to normal
edge connectivity. In essence, this gives the connected components of the
derived graph in which nodes top-level clusters and nodes in the original
graph. This maintains all subgraph structure within a component, even if a
subgraph does not contain any nodes.
- -n
- Do not project subgraph structure. Normally, if
ccomps produces components as graphs distinct from the input graph,
it will define subgraphs which are projections of subgraphs of the input
graph onto the component. (If the projection is empty, no subgraph is
produced.) If this flag is set, the component contains only the relevant
nodes and edges.
- -X node_name
- Prints only the component containing the node
node_name, if any.
- -X# index
- Prints only component number index, if any, starting
at 0.
- -o outfile
- If specified, each graph will be written to a different
file with the names derived from outfile. In particular, if both
-o and -x flags are used, then each connected component is
written to a different file. If outfile does not have a suffix, the
first file will have the name outfile; then next outfile_1,
then next outfile_2, and so on. If outfile has a suffix,
i.e., has the form base.sfx, then the files will be named
base.sfx, base_1.sfx, base_2.sfx, etc.
By default, each input graph is printed, with each connected component given as
a subgraph whose name is a concatenation of the name of the input graph, the
string "_component_" and the number of the component.
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.
RETURN CODES¶
Unless used to extract a single connected component,
ccomps returns
0 if all the input graphs are connected; and non-zero if any graph has
multiple components, or any error occurred. If just extracting a single
component,
ccomps returns
0 on success and non-zero if an error
occurred.
BUGS¶
It is possible, though unlikely, that the names used for connected components
and their subgraphs may conflict with existing subgraph names.
AUTHORS¶
Stephen C. North <north@research.att.com>
Emden R. Gansner <erg@research.att.com>
SEE ALSO¶
gc(1),
dot(1),
gvpr(1),
gvcolor(1),
acyclic(1),
sccmap(1),
tred(1),
libgraph(3)