# nauty-ransubg - Man Page

extract random graph/digraph from a file of graphs

## Synopsis

**ransubg** [*-lq*] [*-P#|-P#/#*] [*-z*] [*-o*] [*-m#*] [*-S#*] [*infile* [*outfile*]]

## Description

Extract random graph/digraphs of a file of graphs.

The output file has a header if and only if the input file does. The output format is defined by the header or first graph,

but is always digraph6 if **-z** is used.

- -z
Treat the input as a directed graph

- -o
Treat the input as a directed graph and output an oriented graph

- -P# or
**-P**#/# Specify a probability p.

**-P**# is the same as**-P1**/#- -m#
Make this many outputs for each input (default 1)

- -l
Canonically label outputs.

- -S#
Set seed for random numbers (default nondeterministic)

Usually each edge is kept with probability p. In the case of

**-o**, each edge in one direction only is keptwith probability p. For edges in both directions, with probability p keep one direction randomly chosen and with probability 1-p delete both directions. Thus

**-oP1**will make a random orientation of an undirected graph.- -q
Suppress auxiliary information.