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sagemath
GitHub Repository: sagemath/sagesmc
 Path: blob/master/src/sage/combinat/designs/design_catalog.py
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r"""

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Catalog of designs

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This module gathers all designs that can be reached from a Sage sessions

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through the ``designs`` objects. In order to create the Witt design on 24 points

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it is sufficient to type::

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    sage: designs.WittDesign(24) # optional - gap_packages

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    Incidence structure with 24 points and 759 blocks

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Or a Steiner Triple System on 19 points::

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    sage: designs.steiner_triple_system(19)

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    Incidence structure with 19 points and 57 blocks

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Online database -- Jolla Covering Repository (LJCR) :

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There exists an online database of the best known covering designs, the La Jolla

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Covering Repository (LJCR), available at [1]_. As it is over 60MB and changes

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frequently that database is not included in Sage, but one can obtain individual

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coverings and block designs from the LJCR using the method

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:meth:`designs.best_known_covering_design_from_LJCR

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<sage.combinat.designs.covering_design.best_known_covering_design_www>`::

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    sage: C = designs.best_known_covering_design_from_LJCR(7, 3, 2)   # optional - internet

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    sage: C                            # optional - internet

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    (7,3,2)-covering design of size 7

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    Lower bound: 7

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    Method: lex covering

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    Submitted on: 1996-12-01 00:00:00

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    sage: C.incidence_structure()      # optional - internet

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    Incidence structure with 7 points and 7 blocks

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Currently, this module gathers the following designs :

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.. csv-table::

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    :class: contentstable

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    :widths: 100

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    :delim: |

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    :meth:`~sage.combinat.designs.block_design.ProjectiveGeometryDesign`

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    :meth:`~sage.combinat.designs.block_design.ProjectivePlaneDesign`

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    :meth:`~sage.combinat.designs.block_design.AffineGeometryDesign`

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    :meth:`~sage.combinat.designs.block_design.WittDesign`

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    :meth:`~sage.combinat.designs.block_design.HadamardDesign`

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    :meth:`~sage.combinat.designs.block_design.steiner_triple_system`

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    :meth:`~sage.combinat.designs.block_design.steiner_quadruple_system`

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And the :meth:`designs.best_known_covering_design_from_LJCR

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<sage.combinat.designs.covering_design.best_known_covering_design_www>` function

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which queries the LJCR.

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.. TODO::

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    Implement DerivedDesign, ComplementaryDesign, and Hadamard3Design

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REFERENCES:

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.. [1] La Jolla Covering Repository,

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  http://www.ccrwest.org/cover.html

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"""

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from sage.combinat.designs.block_design import (ProjectiveGeometryDesign,

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                                                ProjectivePlaneDesign,

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                                                AffineGeometryDesign,

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                                                WittDesign,

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                                                HadamardDesign,

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                                                steiner_triple_system)

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from sage.combinat.designs.steiner_quadruple_systems import steiner_quadruple_system

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from sage.combinat.designs.covering_design import best_known_covering_design_www as best_known_covering_design_from_LJCR

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