gvgen1

Usage

Overview

gvgen generates a variety of simple, regularly-structured abstract graphs.

Options

The following options are supported:

-c n

Generate a cycle with n vertices and edges.

-C x,y

Generate an x by y cylinder. This will have x*y vertices and 2*x*y - y edges.

-g [f]x,y

Generate an x by y grid. If f is given, the grid is folded, with an edge attaching each pair of opposing corner vertices. This will have x*y vertices and 2*x*y - y - x edges if unfolded and 2*x*y - y - x + 2 edges if folded.

-G [f]x,y

Generate an x by y partial grid. If f is given, the grid is folded, with an edge attaching each pair of opposing corner vertices. This will have x*y vertices.

-h n

Generate a hypercube of degree n. This will have 2^n vertices and n*2^(n-1) edges.

-k n

Generate a complete graph on n vertices with n*(n-1)/2 edges.

-b x,y

Generate a complete x by y bipartite graph. This will have x+y vertices and x*y edges.

-B x,y

Generate an x by y ball, i.e., an x by y cylinder with two "cap" nodes closing the ends. This will have x*y + 2 vertices and 2*x*y + y edges.

-m n

Generate a triangular mesh with n vertices on a side. This will have (n+1)*n/2 vertices and 3*(n-1)*n/2 edges.

-M x,y

Generate an x by y Moebius strip. This will have x*y vertices and 2*x*y - y edges.

-p n

Generate a path on n vertices. This will have n-1 edges.

-r x,y

Generate a random graph. The number of vertices will be the largest value of the form 2^n-1 less than or equal to x. Larger values of y increase the density of the graph.

-R x

Generate a random rooted tree on x vertices.

-s n

Generate a star on n vertices. This will have n-1 edges.

-S n

Generate a Sierpinski graph of order n. This will have 3*(3^(n-1) + 1)/2 vertices and 3^n edges.

-S n,d

Generate a d-dimensional Sierpinski graph of order n. At present, d must be 2 or 3. For d equal to 3, there will be 4*(4^(n-1) + 1)/2 vertices and 6 * 4^(n-1) edges.

-t n

Generate a binary tree of height n. This will have 2^n-1 vertices and 2^n-2 edges.

-t h,n

Generate a n-ary tree of height h.

-T x,y

-T x,y,u,v

Generate an x by y torus. This will have x*y vertices and 2*x*y edges. If u and v are given, they specify twists of that amount in the horizontal and vertical directions, respectively.

-u seed

Specify the initial state for the random number generator. If this option is not given, the current time is used to derive a seed.

-w n

Generate a path on n vertices. This will have n-1 edges.

-i n

Generate n graphs of the requested type. At present, only available if the -R flag is used.

-n prefix

Normally, integers are used as node names. If prefix is specified, this will be prepended to the integer to create the name.

-N name

Use name as the name of the graph. By default, the graph is anonymous.

-o outfile

If specified, the generated graph is written into the file outfile. Otherwise, the graph is written to standard out.

-d

Make the generated graph directed.

-v

Verbose output.

-?

Print usage information.

Exit status

gvgen exits with 0 on successful completion, and exits with 1 if given an ill-formed or incorrect flag, or if the specified output file could not be opened.