/**
* 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.tools.math.function.aggregation;
import java.util.HashMap;
import com.rapidminer.example.Attribute;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
/**
* Calculates the mode of some values.
*
* @author Tobias Malbrecht
*
*/
public class ModeFunction extends AbstractAggregationFunction {
private HashMap<Double, Double> valueWeightMap;
private double maximumValueWeight;
private double valueMaximumWeight;
public ModeFunction() {
this(DEFAULT_IGNORE_MISSINGS);
}
public ModeFunction(Boolean ignoreMissings) {
super(ignoreMissings);
valueWeightMap = new HashMap<Double, Double>();
maximumValueWeight = Double.NEGATIVE_INFINITY;
valueMaximumWeight = Double.NaN;
}
@Override
public String getName() {
return "mode";
}
@Override
protected void reset() {
foundMissing = false;
maximumValueWeight = 0;
valueMaximumWeight = Double.NaN;
if (valueWeightMap != null) {
valueWeightMap.clear();
}
}
@Override
public void update(double value, double weight) {
if (Double.isNaN(value)) {
foundMissing = true;
return;
}
Double totalValueWeight = valueWeightMap.get(value);
if (totalValueWeight != null) {
totalValueWeight += weight;
} else {
totalValueWeight = new Double(weight);
}
valueWeightMap.put(value, totalValueWeight);
if (totalValueWeight.doubleValue() > maximumValueWeight) {
maximumValueWeight = totalValueWeight;
valueMaximumWeight = value;
}
}
@Override
public void update(double value) {
if (Double.isNaN(value)) {
foundMissing = true;
return;
}
Double totalValueWeight = valueWeightMap.get(value);
if (totalValueWeight != null) {
totalValueWeight++;
} else {
totalValueWeight = new Double(1);
}
valueWeightMap.put(value, totalValueWeight);
if (totalValueWeight > maximumValueWeight) {
maximumValueWeight = totalValueWeight;
valueMaximumWeight = value;
}
}
@Override
public double getValue() {
if (foundMissing && !ignoreMissings) {
return Double.NaN;
}
return valueMaximumWeight;
}
@Override
public boolean supportsAttribute(Attribute attribute) {
return true;
}
@Override
public boolean supportsAttribute(AttributeMetaData amd) {
return true;
}
@Override
public boolean supportsValueType(int valueType) {
return true;
}
}