/** * Copyright (C) 2001-2017 by RapidMiner and the contributors * * Complete list of developers available at our web site: * * http://rapidminer.com * * This program is free software: you can redistribute it and/or modify it under the terms of the * GNU Affero General Public License as published by the Free Software Foundation, either version 3 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License along with this program. * If not, see http://www.gnu.org/licenses/. */ package com.rapidminer.operator.preprocessing.filter; import com.rapidminer.example.AttributeRole; import com.rapidminer.example.ExampleSet; import com.rapidminer.operator.OperatorDescription; import com.rapidminer.operator.OperatorException; import com.rapidminer.operator.features.selection.AbstractFeatureSelection; import com.rapidminer.parameter.ParameterType; import com.rapidminer.parameter.ParameterTypeBoolean; import java.util.Iterator; import java.util.List; /** * This is an abstract superclass for feature filters. These operators take an * <code>ExampleSet</code> as input and switch off all features that fulfill a condition. Subclasses * must implement the condition in the method <code>switchOffFeature()</code>, which returns a * boolean. * * @author Ingo Mierswa */ public abstract class FeatureFilter extends AbstractFeatureSelection { /** The parameter name for "Filter also special attributes (label, id...)" */ public static final String PARAMETER_FILTER_SPECIAL_FEATURES = "filter_special_features"; public FeatureFilter(OperatorDescription description) { super(description); } /** * Must be implemented by subclasses. When operators extending this class are applied, they loop * through the set of features and switch off all features for which this method returns TRUE, * while keeping the status of the other features. * * @param theFeature * Feature to check. * @return TRUE if this feature should <b>not</b> be active in the output example set of this * operator. FALSE otherwise. */ public abstract boolean switchOffFeature(AttributeRole theFeature) throws OperatorException; /** * Applies filtering of features by looping through all features and checking * <code>switchOffFeature()</code>. If TRUE is returned, the feature is switched off, ie it * won't be used by the following operators in the chain. If FALSE is returned by * <code>switchOffFeature()</code>, the feature will keep its previous status. * * @return An array of IOObjects, with the output example set as the only member. */ @Override public ExampleSet apply(ExampleSet eSet) throws OperatorException { log(eSet.getAttributes().size() + " features before filtering."); Iterator<AttributeRole> i = eSet.getAttributes().allAttributeRoles(); boolean filterSpecial = getParameterAsBoolean(PARAMETER_FILTER_SPECIAL_FEATURES); while (i.hasNext()) { AttributeRole role = i.next(); if ((role.isSpecial()) && (!filterSpecial)) { continue; } if (switchOffFeature(role)) { i.remove(); } checkForStop(); } log(eSet.getAttributes().size() + " features left after filtering."); return eSet; } @Override public List<ParameterType> getParameterTypes() { List<ParameterType> types = super.getParameterTypes(); types.add(new ParameterTypeBoolean(PARAMETER_FILTER_SPECIAL_FEATURES, "Filter also special attributes (label, id...)", false)); return types; } }