Parameters for Seymour decomposition algorithm. More...

#include <seymour.h>

Public Attributes
bool	stopWhenIrregular
	Whether to stop decomposing once irregularity is determined. More...

bool	stopWhenNongraphic
	Whether to stop decomposing once non-graphicness (or being non-network) is determined. More...

bool	stopWhenNoncographic
	Whether to stop decomposing once non-cographicness (or being non-conetwork) is determined. More...

bool	stopWhenNeitherGraphicNorCoGraphic
	Whether to stop decomposing once non-graphicness and non-cographicness (or not being network and not being conetwork) is determined. More...

bool	seriesParallel
	Whether to allow series-parallel operations in the decomposition tree; default: `true`. More...

bool	planarityCheck
	Whether minors identified as graphic should still be checked for cographicness; default: `false`. More...

bool	directGraphicness
	Whether to use fast graphicness routines; default: `true`. More...

bool	preferGraphicness
	Whether to first test for (co)graphicness (or being (co)network) before applying series-parallel reductions. More...

bool	threeSumPivotChildren
	Whether pivots for 3-sums shall be applied such that the matrix contains both child matrices as submatrices, if possible. More...

int	threeSumStrategy
	Whether to perform pivots to change the rank distribution, and how to construct the children. More...

bool	constructLeafGraphs
	Whether to construct (co)graphs for all leaf nodes that are (co)graphic or (co)network. More...

bool	constructAllGraphs
	Whether to construct (co)graphs for all nodes that are (co)graphic or (co)network. More...

Detailed Description

Parameters for Seymour decomposition algorithm.

Member Data Documentation

◆ constructAllGraphs

bool CMR_SEYMOUR_PARAMS::constructAllGraphs

Whether to construct (co)graphs for all nodes that are (co)graphic or (co)network.

◆ constructLeafGraphs

bool CMR_SEYMOUR_PARAMS::constructLeafGraphs

Whether to construct (co)graphs for all leaf nodes that are (co)graphic or (co)network.

◆ directGraphicness

bool CMR_SEYMOUR_PARAMS::directGraphicness

Whether to use fast graphicness routines; default: true.

◆ planarityCheck

bool CMR_SEYMOUR_PARAMS::planarityCheck

Whether minors identified as graphic should still be checked for cographicness; default: false.

◆ preferGraphicness

bool CMR_SEYMOUR_PARAMS::preferGraphicness

Whether to first test for (co)graphicness (or being (co)network) before applying series-parallel reductions.

◆ seriesParallel

bool CMR_SEYMOUR_PARAMS::seriesParallel

Whether to allow series-parallel operations in the decomposition tree; default: true.

◆ stopWhenIrregular

bool CMR_SEYMOUR_PARAMS::stopWhenIrregular

Whether to stop decomposing once irregularity is determined.

◆ stopWhenNeitherGraphicNorCoGraphic

bool CMR_SEYMOUR_PARAMS::stopWhenNeitherGraphicNorCoGraphic

Whether to stop decomposing once non-graphicness and non-cographicness (or not being network and not being conetwork) is determined.

◆ stopWhenNoncographic

bool CMR_SEYMOUR_PARAMS::stopWhenNoncographic

Whether to stop decomposing once non-cographicness (or being non-conetwork) is determined.

◆ stopWhenNongraphic

bool CMR_SEYMOUR_PARAMS::stopWhenNongraphic

Whether to stop decomposing once non-graphicness (or being non-network) is determined.

◆ threeSumPivotChildren

bool CMR_SEYMOUR_PARAMS::threeSumPivotChildren

Whether pivots for 3-sums shall be applied such that the matrix contains both child matrices as submatrices, if possible.

◆ threeSumStrategy

int CMR_SEYMOUR_PARAMS::threeSumStrategy

Whether to perform pivots to change the rank distribution, and how to construct the children.

The value is a bit-wise or of three decisions. The first decision is that of the rank distribution:

CMR_SEYMOUR_THREESUM_FLAG_NO_PIVOTS to not change the rank distribution (default), or
CMR_SEYMOUR_THREESUM_FLAG_DISTRIBUTED_RANKS to enforce distributed ranks (1 + 1), or
CMR_SEYMOUR_THREESUM_FLAG_CONCENTRATED_RANK to enforce concentrated ranks (2 + 0).

The second decision determines the layout of the first child matrix:

CMR_SEYMOUR_THREESUM_FLAG_FIRST_WIDE for a wide first child (default) in case of distributed ranks, or
CMR_SEYMOUR_THREESUM_FLAG_FIRST_TALL for a tall first child in that case.
CMR_SEYMOUR_THREESUM_FLAG_FIRST_MIXED for a mixed first child (default) in case of concentrated ranks, or
CMR_SEYMOUR_THREESUM_FLAG_FIRST_ALLREPR for a first child with all representing rows in that case.

Similarly, the third decision determines the layout of the second child matrix:

CMR_SEYMOUR_THREESUM_FLAG_SECOND_WIDE for a wide second child (default) in case of distributed ranks, or
CMR_SEYMOUR_THREESUM_FLAG_SECOND_TALL for a tall second child in that case.
CMR_SEYMOUR_THREESUM_FLAG_SECOND_MIXED for a mixed second child (default) in case of concentrated ranks, or
CMR_SEYMOUR_THREESUM_FLAG_SECOND_ALLREPR for a first second with all representing rows in that case.

See also: Decomposition of regular matroids for a description of these layouts.

A decomposition as described by Seymour can be selected via CMR_SEYMOUR_THREESUM_FLAG_SEYMOUR. A decomposition as used by Truemper can be selected via CMR_SEYMOUR_THREESUM_FLAG_TRUEMPER. The default is to not carry out any pivots and choose Seymour's or Truemper's definition depending on the rank distribution.

The documentation for this struct was generated from the following file:

/home/runner/work/cmr/cmr/include/cmr/seymour.h

Public Attributes