com.rapidminer.operator.features.construction
Class EquivalentAttributeRemoval

java.lang.Object
  com.rapidminer.operator.features.construction.ExampleSetBasedIndividualOperator
      com.rapidminer.operator.features.construction.EquivalentAttributeRemoval

All Implemented Interfaces:

ExampleSetBasedPopulationOperator

public class EquivalentAttributeRemoval
extends ExampleSetBasedIndividualOperator

If the example set contain two equivalent attributes, the longer representation is removed. The length is calculated as the number of nested brackets. The equivalency probe is not done by structural comparison. The attribute values of the equations in question are randomly sampled and the equation results compared. If the difference is less than epsilon for k trials, the equations are probably equivalent. At least they produce similar values.
The values of the attributes are sampled in the range of the minimum and maximum values of the attribute. This ensures equivalency or at least very similar values for the definition range in question. Therefore a MemoryExampleTable is constructed and filled with random values. Then a ExpressionParser is used to construct the attributes values.

Author:

Ingo Mierswa ingomierswa Exp $

Constructor Summary

EquivalentAttributeRemoval(int numberOfSamples, double epsilon, boolean recalculateAttributeStatistics, RandomGenerator random)
Creates a new equivalent attribute removal population operator.

Method Summary

java.util.List<ExampleSetBasedIndividual>

operate(ExampleSetBasedIndividual individual) Subclasses must implement this method providing a list of new individuals.

Methods inherited from class com.rapidminer.operator.features.construction.ExampleSetBasedIndividualOperator

operate, performOperation

Methods inherited from class java.lang.Object

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

Constructor Detail

EquivalentAttributeRemoval

public EquivalentAttributeRemoval(int numberOfSamples,
                                  double epsilon,
                                  boolean recalculateAttributeStatistics,
                                  RandomGenerator random)

Creates a new equivalent attribute removal population operator.

Method Detail

operate

public java.util.List<ExampleSetBasedIndividual> operate(ExampleSetBasedIndividual individual)

Description copied from class: ExampleSetBasedIndividualOperator

Subclasses must implement this method providing a list of new individuals. individual will be removed from the population so it might be useful to return a list of size 1 containing only the modified individual. If the original individual should also be part of the new population it must also be added to the result list.

Specified by:

operate in class ExampleSetBasedIndividualOperator