# nauty-delptg - Man Page

delete vertices

## Synopsis

**delptg** [*-lq*] [*-a|-b*] [*-d#|-d#:#*] [*-v#|-v#:#*] [*-r#*] [*-n#*] [*-m#|-i*] [*infile* [*outfile*]]

## Description

Delete some vertices from a file of graphs.

The output file has a header if and only if the input file does. No isomorph reduction is done.

- -l
Canonically label outputs

**-d**# **-d**#:# Only remove vertices with original degree in the given range

For digraphs, the out-degree is used.

**-n**# The number of vertices to delete (default 1).

**-v**# **-v**#:# Vertex number or numbers that it is allowed to delete

(the first vertex is number 0).

**-m**# Lower bound on minimum degree of output graphs.

**-r**# Choose # random sets of points (not necessarily different)

- -a
The deleted points must be adjacent.

- -b
The deleted points must be non-adjacent.

- -i
Leave deleted vertices as isolates, not compatible with

**-m**.No empty graphs are output. No warning is issued if

**-d**,**-v -n**,**-m**together imply no graphs are output.For digraphs, out-degree is used for

**-d**and**-m**.**-q**Suppress auxiliary information