#!/usr/bin/perl -w
use strict;

use PDL;
use PDL::IO::Misc;
use PDL::FFT qw(:Func);

use constant TWOPI=>8*atan2 1,1;

my $data = PDL->new([ map { exp(-$_/10) * cos(TWOPI*3*$_/16) } 0..15 ]);

# this is a print routine
print 'Original Data:',$/;
PDL::IO::Misc::wcols($data);

# works in place, modifies $data
realfft($data);

print 'Transformed Data:',$/;
PDL::IO::Misc::wcols($data);

realifft($data);

print 'Restored Data:',$/;
PDL::IO::Misc::wcols($data);