org.aksw.limes.core.execution.engine.filter

Class LinearFilter

java.lang.Object

org.aksw.limes.core.execution.engine.filter.LinearFilter

All Implemented Interfaces:

IFilter

public class LinearFilter
extends Object
implements IFilter

Implements the linear filter class.

Version:

1.0

Author:

Axel-C. Ngonga Ngomo (ngonga@informatik.uni-leipzig.de), Kleanthi Georgala (georgala@informatik.uni-leipzig.de)

Constructor Summary

Constructors

Constructor and Description
LinearFilter()

Method Summary

Modifier and Type	Method and Description
AMapping	filter(AMapping map1, AMapping map2, double coef1, double coef2, double threshold, String operation) Filter for linear combinations when operation is set to "add", given the expression a*sim1 + b*sim2 >= t or multiplication given the expression (a*sim1)*(b*sim2) >= t, which is not likely to be used.
AMapping	filter(AMapping map, double threshold) Naive filter function for mapping using a threshold as filtering criterion.
AMapping	filter(AMapping map, String condition, double threshold, ACache source, ACache target, String sourceVar, String targetVar) Filter function for mapping using a condition and a threshold as filtering criterion.
AMapping	filter(AMapping map, String condition, double threshold, double mainThreshold, ACache source, ACache target, String sourceVar, String targetVar) Filter function for mapping using a condition and two thresholds as filtering criterion.
AMapping	reversefilter(AMapping map, String condition, double threshold, double mainThreshold, ACache source, ACache target, String sourceVar, String targetVar) Reverse filter function for mapping using a condition and two thresholds as filtering criterion.

Methods inherited from class java.lang.Object

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

Constructor Detail

LinearFilter

public LinearFilter()

Method Detail

filter

public AMapping filter(AMapping map,
                       double threshold)

Naive filter function for mapping using a threshold as filtering criterion. The output mapping includes set of links from the initial mapping that have a similarity above the input threshold.

Specified by:

filter in interface IFilter

Parameters:

map - Map bearing the results of Link Specification

threshold - Value of threshold

Returns:

a filtered mapping that satisfies sim >= threshold

filter

public AMapping filter(AMapping map,
                       String condition,
                       double threshold,
                       ACache source,
                       ACache target,
                       String sourceVar,
                       String targetVar)

Filter function for mapping using a condition and a threshold as filtering criterion. The output mapping includes set of links from the initial mapping whose similarity based on the input condition is above the input threshold.

Specified by:

filter in interface IFilter

Parameters:

map - Map bearing the results of Link Specification

condition - The condition for filtering

threshold - Value of threshold

source - Source knowledge base

target - Target knowledge base

sourceVar - Source property

targetVar - Target property

Returns:

a filtered mapping that satisfies both the condition and the threshold

filter

public AMapping filter(AMapping map,
                       String condition,
                       double threshold,
                       double mainThreshold,
                       ACache source,
                       ACache target,
                       String sourceVar,
                       String targetVar)

Filter function for mapping using a condition and two thresholds as filtering criterion. Used by HELIOS/DYNAMIC planner in case of an AND optimization strategy. The input mapping produced by executing one of the children specifications of a specification with an AND operator, will be filtered using the expression and the threshold of the other child. In order for a link to be included in the output mapping, it must also fulfill the input condition and have an initial similarity above the mainThreshold.

Specified by:

filter in interface IFilter

Parameters:

map - map bearing the results of Link Specification

condition - The condition for filtering

threshold - Value of the first threshold

mainThreshold - Value of second threshold

source - Source knowledge base

target - Target knowledge base

sourceVar - Source property

targetVar - Target property

Returns:

a filtered mapping that satisfies both the condition and the thresholds

reversefilter

public AMapping reversefilter(AMapping map,
                              String condition,
                              double threshold,
                              double mainThreshold,
                              ACache source,
                              ACache target,
                              String sourceVar,
                              String targetVar)

Reverse filter function for mapping using a condition and two thresholds as filtering criterion. Used by DYNAMIC planner in case of an MINUS optimization strategy. The input mapping produced by executing the left child of a specification with a MINUS operator, will be filtered by the expression and the threshold of the right child. In order for a link to be included in the output mapping, it must not fulfill the input condition and its initial similarity must be above the mainThreshold.

Specified by:

reversefilter in interface IFilter

Parameters:

map - Map bearing the results of Link Specification

condition - The condition for filtering

threshold - Value of the first threshold

mainThreshold - Value of second threshold

source - Source knowledge base

target - Target knowledge base

sourceVar - Source property

targetVar - Target property

Returns:

a filtered mapping that satisfies both the condition and the thresholds

filter

public AMapping filter(AMapping map1,
                       AMapping map2,
                       double coef1,
                       double coef2,
                       double threshold,
                       String operation)

Filter for linear combinations when operation is set to "add", given the expression a*sim1 + b*sim2 >= t or multiplication given the expression (a*sim1)*(b*sim2) >= t, which is not likely to be used. Implements a filter for the special case of linear combinations and multiplications. The straight forward way would be to compute filter(intersection(m1, m2), linear_combination_condition) leading to re-computations. This implementation avoid that by reusing the similarities that have already been computed.

Specified by:

filter in interface IFilter

Parameters:

map1 - Map bearing the results of sim1 >= (t-b)/a for add, sim1 >= t/(a*b) for mult

map2 - Map bearing the results of sim2 >= (t-a)/b for add, sim2 >= t/(a*b) for mult

coef1 - Value of first coefficient

coef2 - Value of second coefficient

threshold - Value of threshold

operation - Mathematical operation

Returns:

a filtered mapping that satisfies a*sim1 + b*sim2 >= t for add, (a*sim1)*(b*sim2) >= t for mult