---
name: "nauty-delptg"
section: "1"
platform: "linux"
package: "nauty"
version: "2.8.9+ds-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/nauty-delptg"
---

# nauty-delptg(1)

delete vertices

## NAME

nauty-delptg - 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)

**-S**# Set random number seed (taken from clock otherwise).

- **-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