NAME

App::MathImage::Values::Sequence -- base class for number sequences

SYNOPSIS

# only a base class, use one of the actual classes such as

use App::MathImage::Values::Sequence::Squares;
my $seq = App::MathImage::Values::Sequence::Squares->new;
my ($i, $value) = $seq->next;

DESCRIPTION

This is a base class for number sequences. It's a touch rough yet, but the idea is iterate through things like squares or primes in a generic way.

FUNCTIONS

In the following "Foo" is one of the actual subclass names.

$seq = App::MathImage::Values::Sequence::Foo->new (key=>value,...)

Create and return a new sequence object.

($i, $value) = $seq->next()

Return the next index and value in the sequence.

$seq->rewind()

Return the sequence to its starting point.

$str = $seq->description()

A human-readable description of the sequence.

$value = $seq->values_min()

$value = $seq->values_max()

Return the minimum or maximum value taken by values in the sequence, or undef if unknown. Currently if the maximum is infinity then the return is undef too, but perhaps it should be a floating point infinity, if there is one.

$ret = $seq->characteristic($key)

Return true if the sequence is of the given $key (a string) type. This is intended as a loose set of characteristics or properties a sequence might have. The following keys exist currently,

count       a count of something
digits      digits in a given radix

$str = $seq->oeis_anum()

Return the Online Encyclopedia or Integer Sequences A-number for $seq, or undef if $seq is not in the OEIS (so far as is known). For example for the sequence of squares the return is "A000290".

Optional Methods

The following methods are only implemented for some sequences, because for some it can be difficult to generate a particular numbered element etc.

$value = $seq->ith($i)

Return the $i'th value in the sequence. Only some sequence classes implement this method.

$bool = $seq->pred($value)

Return true if $value occurs in the sequence. For example for the squares this would return true if $value is a perfect square or false if not.

SEE ALSO

Math::Sequence and Math::Series, symbolic recursive definitions like Fibonacci

math-image

HOME PAGE

http://user42.tuxfamily.org/math-image/index.html

LICENSE

Copyright 2010, 2011 Kevin Ryde

Math-Image 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-Image 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-Image. If not, see <http://www.gnu.org/licenses/>.