=head1 NAME PDL::Constants -- basic compile time constants for PDL =head1 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. =head1 SYNOPSIS use PDL::Constants qw(PI E); print 'PI is ' . PI . "\n"; print 'E is ' . E . "\n"; =cut package PDL::Constants; our $VERSION = "0.02"; $VERSION = eval $VERSION; require Exporter; @ISA = qw(Exporter); @EXPORT_OK = qw(PI E I J); # symbols to export use PDL::Lite; use PDL::Complex qw(i); =head2 PI The ratio of a circle's circumference to its diameter =cut use constant PI => 4 * atan2(1, 1); =head2 DEGRAD The The number of degrees of arc per radian (180/PI) =cut use constant DEGRAD => 180/PI; =head2 E The base of the natural logarithms or Euler's number =cut use constant E => exp(1); =head2 I The imaginary unit, C< I*I == -1 > =cut use constant I => i; =head2 J The imaginary unit for engineers, C< J*J == -1 > =cut use constant J => i; =head1 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. =cut 1;