/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.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.weighting;

import com.rapidminer.example.Attributes;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.MetaData;
import com.rapidminer.operator.ports.metadata.SetRelation;
import com.rapidminer.operator.preprocessing.AbstractDataProcessing;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.math.container.Range;

/** Abstract superclass of operators adding a weight attribute.
 * 
 * @author Simon Fischer
 *
 */
public abstract class AbstractExampleWeighting extends AbstractDataProcessing {

	public AbstractExampleWeighting(OperatorDescription description) {
		super(description);
	}

	@Override
	protected MetaData modifyMetaData(ExampleSetMetaData metaData) {
		AttributeMetaData weightAttribute = new AttributeMetaData(Attributes.WEIGHT_NAME, Ontology.REAL, Attributes.WEIGHT_NAME);
		weightAttribute.setValueRange(getWeightAttributeRange(), getWeightAttributeValueRelation());
		metaData.addAttribute(weightAttribute);
		return metaData;
	}

	protected Range getWeightAttributeRange() {
		return new Range(Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY);
	}

	protected SetRelation getWeightAttributeValueRelation() {
		return SetRelation.UNKNOWN	;
	}

}