NAME

pds.db - small database with planar difference set samples

VERSION

This is version 1.0 of the database, created on July 30, 2019.

DESCRIPTION

This file is the default database distributed with the Perl 5 module Math::DifferenceSet::Planar.

It contains 604 cyclic planar difference sets with orders ranging from 2 to 4096. The sets are chosen minimal by lexicographic ordering.

FILE FORMAT

SQLite 3.x database.

SCHEMA

CREATE TABLE difference_set (
  order_   integer NOT NULL PRIMARY KEY,
  base     integer NOT NULL,
  exponent integer NOT NULL,
  modulus  integer NOT NULL,
  n_planes integer NOT NULL,
  deltas   blob    NOT NULL
);

DATA REPRESENTATION

If D = { d_1, d_2, ..., d_k } (mod m) is a canonical cyclic planar difference set of order k - 1 with d_1 ≡ 0 and d_2 ≡ 1 (mod m), deltas is a sequence of k - 2 numeric values packed in 'w*' format, calculated as differences of consecutive residue values of D starting with d_3 - d_2. The difference of the smallest two values in a canonical set is always 1 and thus not important to store.

PROVIDER

Martin Becker, <becker-cpan-mp at cozap.com>

COPYRIGHT AND LICENSE

The contents of this database are mathematically defined entities. The provider believes mathematical constants not to be proprietary or subject to copyright legislation, although the software used to calculate them may be.