# Copyright 2010, 2011, 2012, 2013, 2014 Kevin Ryde
# This file is part of Math-NumSeq.
#
# Math-NumSeq is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3, or (at your option) any later
# version.
#
# Math-NumSeq is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Math-NumSeq. If not, see <http://www.gnu.org/licenses/>.
# Christopher Williamson, "An Overview of the Thue-Morse Sequence",
# www.math.washington.edu/~morrow/336_12/papers/christopher.pdf
package Math::NumSeq::DigitLengthModulo;
use 5.004;
use strict;
use vars '$VERSION', '@ISA';
$VERSION = 69;
use Math::NumSeq;
use Math::NumSeq::Base::IterateIth;
@ISA = ('Math::NumSeq::Base::IterateIth',
'Math::NumSeq');
*_is_infinite = \&Math::NumSeq::_is_infinite;
use Math::NumSeq::DigitLength;
# uncomment this to run the ### lines
#use Smart::Comments;
use Math::NumSeq::Base::Digits;
use constant parameter_info_array =>
[ Math::NumSeq::Base::Digits->parameter_info_list,
{ name => 'modulus',
share_key => 'modulus_0',
type => 'integer',
display => Math::NumSeq::__('Modulus'),
default => 0,
minimum => 0,
width => 3,
description => Math::NumSeq::__('Modulus, or 0 to use the radix.'),
},
];
use constant i_start => 0;
use constant characteristic_smaller => 1;
use constant characteristic_integer => 1;
use constant values_min => 0;
sub values_max {
my ($self) = @_;
if (my $modulus = $self->{'modulus'}) {
return $modulus;
}
return $self->{'radix'} - 1;
}
# use constant name => Math::NumSeq::__('Digit Length Modulo');
use constant description => Math::NumSeq::__('Length in digits in the given radix, then modulo that radix or a given modulus.');
my @oeis_anum = (
# OEIS-Catalogue array begin
undef,
undef,
# OEIS-Catalogue array end
);
sub oeis_anum {
my ($self) = @_;
if ($self->{'modulus'} == 1) {
return 'A000004'; # all zeros
}
return $oeis_anum[$self->{'radix'}];
}
sub ith {
my ($self, $i) = @_;
my $radix = $self->{'radix'};
if (_is_infinite ($i)) {
return $i;
}
my $value = $self->Math::NumSeq::DigitLength::ith($i);
if (my $modulus = $self->{'modulus'}) {
return $value % $modulus;
}
return $value % $radix;
}
sub pred {
my ($self, $value) = @_;
return ($value == int($value)
&& $value >= 0
&& $value <= $self->values_max);
}
1;
__END__