/**
* 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.learner.lazy;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.OperatorProgress;
import com.rapidminer.operator.learner.PredictionModel;
import com.rapidminer.tools.Tools;
/**
* The default model sets the prediction of all examples to the mode value in case of nominal labels
* and to the average value in case of numerical labels.
*
* @author Stefan Rueping, Ingo Mierswa
*/
public class DefaultModel extends PredictionModel {
private static final long serialVersionUID = -1455906287520811107L;
private static final int OPERATOR_PROGRESS_STEPS = 10_000;
/** The default prediction. */
private double value;
/** The confidence values for all predictions. */
private double[] confidences;
/** Can be used to create a default model for regression tasks. */
public DefaultModel(ExampleSet exampleSet, double value) {
this(exampleSet, value, null);
}
/**
* Can be used to create a default model for classification tasks (confidence values should not
* be null in this case).
*/
public DefaultModel(ExampleSet exampleSet, double value, double[] confidences) {
super(exampleSet, null, null);
this.value = value;
this.confidences = confidences;
}
/** Iterates over all examples and applies the model to them. */
@Override
public ExampleSet performPrediction(ExampleSet exampleSet, Attribute predictedLabelAttribute) throws OperatorException {
Attribute label = getLabel();
OperatorProgress progress = null;
if (getShowProgress() && getOperator() != null && getOperator().getProgress() != null) {
progress = getOperator().getProgress();
progress.setTotal(exampleSet.size());
}
int progressCounter = 0;
for (Example example : exampleSet) {
example.setValue(predictedLabelAttribute, value);
if (label.isNominal()) {
for (int i = 0; i < confidences.length; i++) {
example.setConfidence(predictedLabelAttribute.getMapping().mapIndex(i), confidences[i]);
}
}
if (progress != null && ++progressCounter % OPERATOR_PROGRESS_STEPS == 0) {
progress.setCompleted(progressCounter);
}
}
return exampleSet;
}
@Override
public String toString() {
return super.toString() + Tools.getLineSeparator() + "default value: "
+ (getLabel().isNominal() ? getLabel().getMapping().mapIndex((int) value) : value + "");
}
public double getValue() {
return value;
}
public double[] getConfidences() {
return confidences;
}
}