/*
* Encog(tm) Core v3.4 - Java Version
* http://www.heatonresearch.com/encog/
* https://github.com/encog/encog-java-core
* Copyright 2008-2016 Heaton Research, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.ml.fitting.linear;
import org.encog.EncogError;
import org.encog.ml.MLError;
import org.encog.ml.MLRegression;
import org.encog.ml.data.MLData;
import org.encog.ml.data.MLDataSet;
import org.encog.ml.data.basic.BasicMLData;
import org.encog.util.simple.EncogUtility;
public class LinearRegression implements MLRegression, MLError {
private double[] weights;
private int inputCount;
public LinearRegression(int theInputCount) {
if( theInputCount!=1 ) {
throw new EncogError("Input size must be one.");
}
this.inputCount = theInputCount;
this.weights = new double[theInputCount+1];
}
public double[] getWeights() {
return weights;
}
@Override
public int getInputCount() {
return this.inputCount;
}
@Override
public int getOutputCount() {
return 1;
}
@Override
public MLData compute(MLData input) {
if( input.size()!=this.inputCount) {
throw new EncogError("Invalid input size, must be " + inputCount);
}
double[] sum = new double[1];
sum[0] += this.weights[0];
for(int i=0;i<input.size();i++) {
sum[0] += this.weights[i+1] * Math.pow(input.getData(i),i+1);
}
return new BasicMLData(sum);
}
@Override
public double calculateError(MLDataSet data) {
return EncogUtility.calculateRegressionError(this, data);
}
}