**See also:**How do I search for a function?

# PDL::Constants

# NAME

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

# DESCRIPTION

This module is used to define compile time constant values for PDL. It uses the constant module for simplicity and availability. We'll need to sort out exactly which constants make sense but PI and E seem to be fundamental.

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

## E

The base of the natural logarithms or Euler's number

## I

The imaginary unit, ` I*I == -1 `

## J

The imaginary unit for engineers, ` J*J == -1 `

# 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.