jhypercomplex.combinatorics

Class SevenPointsSTS

java.lang.Object

jhypercomplex.combinatorics.SteinerTripleSystem

jhypercomplex.combinatorics.SevenPointsSTS

public class SevenPointsSTS
extends SteinerTripleSystem

Copyright © 2005-2015 by Markus Maute. All rights reserved.

Author:

Markus Maute (http:///www.jalgebra.com)

Constructor Summary

Constructors

Constructor and Description
SevenPointsSTS()

Method Summary

Methods

Modifier and Type	Method and Description
int[]	getRepresentation()
boolean	isSTS7() As the blocks can be set externally it is not guaranteed that one gets a block design.
void	setRepresentation(int class_nr, int nr) For STS(7) there exist 30 inequivalent labelings.
void	setTriple(int nr, java.lang.String[] triple) Sets one of the 7 triples of a STS(7).

Methods inherited from class jhypercomplex.combinatorics.SteinerTripleSystem

asString, getNumberOfBlocks, getNumberOfPoints, getTriples, isEqual

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SevenPointsSTS

public SevenPointsSTS()

Method Detail

setRepresentation

public void setRepresentation(int class_nr,
                     int nr)
                       throws java.lang.Exception

For STS(7) there exist 30 inequivalent labelings. They naturally fall into 2 classes a 15 systems: Class 1: Nr. 1 (1,2,3) (1,4,5) (1,6,7) (2,4,7) (2,5,6) (3,4,6) (3,5,7) 2 (1,2,3) (1,4,6) (1,5,7) (2,4,5) (2,6,7) (3,4,7) (3,5,6) 3 (1,2,3) (1,4,7) (1,5,6) (2,4,6) (2,5,7) (3,4,5) (3,6,7) 4 (1,2,4) (1,3,5) (1,6,7) (2,3,6) (2,5,7) (3,4,7) (4,5,6) 5 (1,2,4) (1,3,6) (1,5,7) (2,3,7) (2,5,6) (3,4,5) (4,6,7) 6 (1,2,4) (1,3,7) (1,5,6) (2,3,5) (2,6,7) (3,4,6) (4,5,7) 7 (1,2,5) (1,3,4) (1,6,7) (2,3,7) (2,4,6) (3,5,6) (4,5,7) 8 (1,2,5) (1,3,6) (1,4,7) (2,3,4) (2,6,7) (3,5,7) (4,5,6) 9 (1,2,5) (1,3,7) (1,4,6) (2,3,6) (2,4,7) (3,4,5) (5,6,7) 10 (1,2,6) (1,3,4) (1,5,7) (2,3,5) (2,4,7) (3,6,7) (4,5,6) 11 (1,2,6) (1,3,5) (1,4,7) (2,3,7) (2,4,5) (3,4,6) (5,6,7) 12 (1,2,6) (1,3,7) (1,4,5) (2,3,4) (2,5,7) (3,5,6) (4,6,7) 13 (1,2,7) (1,3,4) (1,5,6) (2,3,6) (2,4,5) (3,5,7) (4,6,7) 14 (1,2,7) (1,3,5) (1,4,6) (2,3,4) (2,5,6) (3,6,7) (4,5,7) 15 (1,2,7) (1,3,6) (1,4,5) (2,3,5) (2,4,6) (3,4,7) (5,6,7) Class 2: Nr. 1 (1,2,3) (1,4,5) (1,6,7) (2,4,6) (2,5,7) (3,4,7) (3,5,6) 2 (1,2,3) (1,4,6) (1,5,7) (2,4,7) (2,5,6) (3,4,5) (3,6,7) 3 (1,2,3) (1,4,7) (1,5,6) (2,4,5) (2,6,7) (3,4,6) (3,5,7) 4 (1,2,4) (1,3,5) (1,6,7) (2,3,7) (2,5,6) (3,4,6) (4,5,7) 5 (1,2,4) (1,3,6) (1,5,7) (2,3,5) (2,6,7) (3,4,7) (4,5,6) 6 (1,2,4) (1,3,7) (1,5,6) (2,3,6) (2,5,7) (3,4,5) (4,6,7) 7 (1,2,5) (1,3,4) (1,6,7) (2,3,6) (2,4,7) (3,5,7) (4,5,6) 8 (1,2,5) (1,3,6) (1,4,7) (2,3,7) (2,4,6) (3,4,5) (5,6,7) 9 (1,2,5) (1,3,7) (1,4,6) (2,3,4) (2,6,7) (3,5,6) (4,5,7) 10 (1,2,6) (1,3,4) (1,5,7) (2,3,7) (2,4,5) (3,5,6) (4,6,7) 11 (1,2,6) (1,3,5) (1,4,7) (2,3,4) (2,5,7) (3,6,7) (4,5,6) 12 (1,2,6) (1,3,7) (1,4,5) (2,3,5) (2,4,7) (3,4,6) (5,6,7) 13 (1,2,7) (1,3,4) (1,5,6) (2,3,5) (2,4,6) (3,6,7) (4,5,7) 14 (1,2,7) (1,3,5) (1,4,6) (2,3,6) (2,4,5) (3,4,7) (5,6,7) 15 (1,2,7) (1,3,6) (1,4,5) (2,3,4) (2,5,6) (3,5,7) (4,6,7)

Parameters:

class_nr - 1 or 2. // TODO how to identify the 2 classes //

nr - Number of STS(7) within one of the classes. 'nr' is defined by the lexicographical sorting order.

Throws:

java.lang.Exception

isSTS7

public boolean isSTS7()
               throws java.lang.Exception

As the blocks can be set externally it is not guaranteed that one gets a block design. This method checks if it one of the 30 possible designs.

Throws:

java.lang.Exception

setTriple

public void setTriple(int nr,
             java.lang.String[] triple)
               throws java.lang.Exception

Sets one of the 7 triples of a STS(7). No consistency check is carried out. (Checks can be done via "isSTS7"-method).

Parameters:

nr - Number of triple 1,...,7.

triple - Triple (numbering convention is "1", "2", ... "7".

Throws:

java.lang.Exception

getRepresentation

public int[] getRepresentation()
                        throws java.lang.Exception

Parameters:

sts - Steiner triple system on 7 points.

Returns:

2-dimensional integer array with the class number of the representation in the first position and the number in the second one.

Throws:

java.lang.Exception