---
name: "PDL::Constants"
section: "3pm"
platform: "linux"
package: "pdl"
version: "1:2.100-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/PDL::Constants"
---

# PDL::Constants(3pm)

## NAME

PDL::Constants -- basic compile time constants for PDL

## DESCRIPTION

This module is used to define compile time constant values for PDL.  It uses Perl's constant pragma for simplicity and availability.

## SYNOPSIS

```
 use PDL::Constants qw(PI E);
 print 'PI is ' . PI . "\n";
 print 'E  is ' .  E . "\n";
```

### PI

The ratio of a circle's circumference to its diameter

### DEGRAD

The number of degrees of arc per radian (180/PI)

### E

The base of the natural logarithms or Euler's number

## COPYRIGHT & LICENSE

Copyright 2010 Chris Marshall (chm at cpan dot org).

This program is free software; you can redistribute it and/or modify it under the terms of either: the GNU General Public License as published by the Free Software Foundation; or the Artistic License.

See http://dev.perl.org/licenses/ for more information.