org.kramerlab.bmad.algorithms

Class Cover

java.lang.Object

org.kramerlab.bmad.algorithms.Cover

public class Cover
extends Object

A structure that stores all information necessary to predict changes of a weighted cover function for one single row. This implementation properly handles unknown values, which turned out to be not really necessary, since all unknown values are usually removed from the basis vectors. Theoretically, this implementation would be more useful, if one changed the reconstruction error function in a way that predicting an unknown value is rewarded. Works only for basis dimensions less than 2^15

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	entries
protected double	onesWeight
protected int	width

Constructor Summary

Constructors

Constructor and Description
Cover(int width, double onesWeight) Constructs a cover row

Method Summary

Methods

Modifier and Type	Method and Description
Tuple<Integer,Integer>	apply(int c) returns tuple (#TRUE, #UNKNOWN)
double	coverChangeDensityOnInclusion(BooleanMatrix coveredRow, BooleanMatrix basisRow) weighted cover change (indicating "direction" of the change), divided by the weighted number of changed entries (indicating "magnitude" of the change)
double	coverChangeOnExclusion(BooleanMatrix coveredRow, BooleanMatrix basisRow) analogous to coverChangeOnInclusion
double	coverChangeOnInclusion(BooleanMatrix coveredRow, BooleanMatrix basisRow) weighted sum of the results returned by coveredOnesAndZerosOnInclusion
Tuple<Integer,Integer>	coveredOnesAndZerosOnInclusion(BooleanMatrix coveredRow, BooleanMatrix basisRow) Predicts the number of covered ones and zeros, given the row that is being covered, and the basis row that could be included into this cover.
boolean	equals(Object obj)
void	exclude(BooleanMatrix basisRow) Excludes a basis row from this cover
int	hashCode()
void	include(BooleanMatrix basisRow) Includes a basis row into this cover
BooleanMatrix	toBooleanMatrix() transforms this cover to a boolean matrix
String	toString()
Tuple<Integer,Integer>	uncoveredOnesAndZerosOnExclusion(BooleanMatrix coveredRow, BooleanMatrix basisRow) analogous to coveredOnesAndZerosOnInclusion
void	update(int c, int ones, int unknowns) updates entry of this cover
Cover	zero(int width) Creates a new zero cover of specified width

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

onesWeight

protected double onesWeight

width

protected int width

entries

protected int[] entries

Constructor Detail

Cover

public Cover(int width,
     double onesWeight)

Constructs a cover row

Parameters:

width -

onesWeight -

Method Detail

apply

public Tuple<Integer,Integer> apply(int c)

returns tuple (#TRUE, #UNKNOWN)

Parameters:

c - index of the column

Returns:

update

public void update(int c,
          int ones,
          int unknowns)

updates entry of this cover

Parameters:

c - index of a column

ones - #TRUE

unknowns - #UNKNOWN

include

public void include(BooleanMatrix basisRow)

Includes a basis row into this cover

Parameters:

basisRow -

exclude

public void exclude(BooleanMatrix basisRow)

Excludes a basis row from this cover

Parameters:

basisRow -

coveredOnesAndZerosOnInclusion

public Tuple<Integer,Integer> coveredOnesAndZerosOnInclusion(BooleanMatrix coveredRow,
                                                    BooleanMatrix basisRow)

Predicts the number of covered ones and zeros, given the row that is being covered, and the basis row that could be included into this cover. Has no side effects.

Parameters:

coveredRow - boolean matrix row, this cover is associated with

basisRow - boolean matrix row, that potentially could be included into this cover

Returns:

(#1, #0) covered in case of inclusion

uncoveredOnesAndZerosOnExclusion

public Tuple<Integer,Integer> uncoveredOnesAndZerosOnExclusion(BooleanMatrix coveredRow,
                                                      BooleanMatrix basisRow)

analogous to coveredOnesAndZerosOnInclusion

Parameters:

coveredRow -

basisRow -

Returns:

coverChangeOnInclusion

public double coverChangeOnInclusion(BooleanMatrix coveredRow,
                            BooleanMatrix basisRow)

weighted sum of the results returned by coveredOnesAndZerosOnInclusion

Parameters:

coveredRow -

basisRow -

Returns:

onesWeight * #1 + #0

coverChangeOnExclusion

public double coverChangeOnExclusion(BooleanMatrix coveredRow,
                            BooleanMatrix basisRow)

analogous to coverChangeOnInclusion

Parameters:

coveredRow -

basisRow -

Returns:

coverChangeDensityOnInclusion

public double coverChangeDensityOnInclusion(BooleanMatrix coveredRow,
                                   BooleanMatrix basisRow)

weighted cover change (indicating "direction" of the change), divided by the weighted number of changed entries (indicating "magnitude" of the change)

Parameters:

coveredRow -

basisRow -

Returns:

toBooleanMatrix

public BooleanMatrix toBooleanMatrix()

transforms this cover to a boolean matrix

zero

public Cover zero(int width)

Creates a new zero cover of specified width

Parameters:

width -

Returns:

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object