/**
* Copyright 2010 Neuroph Project http://neuroph.sourceforge.net
*
* 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.
*/
package org.neuroph.contrib.samples;
import java.text.NumberFormat;
import org.neuroph.core.NeuralNetwork;
import org.neuroph.core.data.DataSet;
import org.neuroph.core.data.DataSetRow;
import org.neuroph.core.events.LearningEvent;
import org.neuroph.core.events.LearningEventListener;
import org.neuroph.core.learning.SupervisedLearning;
import org.neuroph.nnet.MultiLayerPerceptron;
import org.neuroph.util.Neuroph;
import org.neuroph.util.TransferFunctionType;
/**
* This example shows how to use Neuroph to predict sunspots.
*
* It demonstrates two very important machine learning techniques.
*
* First, time-window. Sunspots are organized into input windows used
* to predict the next level of sunspot activity. This example uses a
* 30 year window. Basically, 30 years of sunspot activity is used to
* predict the 31st year. This 30 year window slides forward, one year
* at a time.
*
* Second is normalization. The sunspots are normalized into a
* range between 0.1 and 0.9. This is very close to the actual
* 0 to 1 range of the sigmoid function. We stay away from the
* extream edges of this range, thus using 0.1 and 0.9.
*
* This is an example from the book "Introduction to Neural Networks
* for Java" by Jeff Heaton. This example has been contributed
* to the Neuroph project by Jeff Heaton.
*
* http://www.heatonresearch.com/book/programming-neural-networks-java-2.html
*
* @author Jeff Heaton (http://www.heatonresearch.com
*
*/
public class SunSpots implements LearningEventListener {
public final static double[] SUNSPOTS = {
0.0262, 0.0575, 0.0837, 0.1203, 0.1883, 0.3033,
0.1517, 0.1046, 0.0523, 0.0418, 0.0157, 0.0000,
0.0000, 0.0105, 0.0575, 0.1412, 0.2458, 0.3295,
0.3138, 0.2040, 0.1464, 0.1360, 0.1151, 0.0575,
0.1098, 0.2092, 0.4079, 0.6381, 0.5387, 0.3818,
0.2458, 0.1831, 0.0575, 0.0262, 0.0837, 0.1778,
0.3661, 0.4236, 0.5805, 0.5282, 0.3818, 0.2092,
0.1046, 0.0837, 0.0262, 0.0575, 0.1151, 0.2092,
0.3138, 0.4231, 0.4362, 0.2495, 0.2500, 0.1606,
0.0638, 0.0502, 0.0534, 0.1700, 0.2489, 0.2824,
0.3290, 0.4493, 0.3201, 0.2359, 0.1904, 0.1093,
0.0596, 0.1977, 0.3651, 0.5549, 0.5272, 0.4268,
0.3478, 0.1820, 0.1600, 0.0366, 0.1036, 0.4838,
0.8075, 0.6585, 0.4435, 0.3562, 0.2014, 0.1192,
0.0534, 0.1260, 0.4336, 0.6904, 0.6846, 0.6177,
0.4702, 0.3483, 0.3138, 0.2453, 0.2144, 0.1114,
0.0837, 0.0335, 0.0214, 0.0356, 0.0758, 0.1778,
0.2354, 0.2254, 0.2484, 0.2207, 0.1470, 0.0528,
0.0424, 0.0131, 0.0000, 0.0073, 0.0262, 0.0638,
0.0727, 0.1851, 0.2395, 0.2150, 0.1574, 0.1250,
0.0816, 0.0345, 0.0209, 0.0094, 0.0445, 0.0868,
0.1898, 0.2594, 0.3358, 0.3504, 0.3708, 0.2500,
0.1438, 0.0445, 0.0690, 0.2976, 0.6354, 0.7233,
0.5397, 0.4482, 0.3379, 0.1919, 0.1266, 0.0560,
0.0785, 0.2097, 0.3216, 0.5152, 0.6522, 0.5036,
0.3483, 0.3373, 0.2829, 0.2040, 0.1077, 0.0350,
0.0225, 0.1187, 0.2866, 0.4906, 0.5010, 0.4038,
0.3091, 0.2301, 0.2458, 0.1595, 0.0853, 0.0382,
0.1966, 0.3870, 0.7270, 0.5816, 0.5314, 0.3462,
0.2338, 0.0889, 0.0591, 0.0649, 0.0178, 0.0314,
0.1689, 0.2840, 0.3122, 0.3332, 0.3321, 0.2730,
0.1328, 0.0685, 0.0356, 0.0330, 0.0371, 0.1862,
0.3818, 0.4451, 0.4079, 0.3347, 0.2186, 0.1370,
0.1396, 0.0633, 0.0497, 0.0141, 0.0262, 0.1276,
0.2197, 0.3321, 0.2814, 0.3243, 0.2537, 0.2296,
0.0973, 0.0298, 0.0188, 0.0073, 0.0502, 0.2479,
0.2986, 0.5434, 0.4215, 0.3326, 0.1966, 0.1365,
0.0743, 0.0303, 0.0873, 0.2317, 0.3342, 0.3609,
0.4069, 0.3394, 0.1867, 0.1109, 0.0581, 0.0298,
0.0455, 0.1888, 0.4168, 0.5983, 0.5732, 0.4644,
0.3546, 0.2484, 0.1600, 0.0853, 0.0502, 0.1736,
0.4843, 0.7929, 0.7128, 0.7045, 0.4388, 0.3630,
0.1647, 0.0727, 0.0230, 0.1987, 0.7411, 0.9947,
0.9665, 0.8316, 0.5873, 0.2819, 0.1961, 0.1459,
0.0534, 0.0790, 0.2458, 0.4906, 0.5539, 0.5518,
0.5465, 0.3483, 0.3603, 0.1987, 0.1804, 0.0811,
0.0659, 0.1428, 0.4838, 0.8127
};
/**
* Starting year for sunspot data.
*/
public final static int STARTING_YEAR = 1700;
/**
* Size of our prediction window.
*/
public final static int WINDOW_SIZE = 30;
/**
* Start of training data.
*/
public final static int TRAIN_START = WINDOW_SIZE;
/**
* End of training data.
*/
public final static int TRAIN_END = 259;
/**
* Beginning of evaluation data.
*/
public final static int EVALUATE_START = 260;
/**
* End of evaluation data.
*/
public final static int EVALUATE_END = SUNSPOTS.length - 1;
/**
* This really should be lowered, I am setting it to a level here that will
* train in under a minute.
*/
public final static double MAX_ERROR = 0.06;
/**
* Normalized sunspots.
*/
private double[] normalizedSunspots;
/**
* Closed loop sunspots. Closed loop means use the neural network output
* as the input for the next prediction, rather than actual data.
*/
private double[] closedLoopSunspots;
private double mean;
/**
* Normalize the sunspots.
* @param lo Low range for normalization.
* @param hi High range for normalization.
*/
public void normalizeSunspots(double lo, double hi) {
double min = Double.MAX_VALUE;
double max = Double.MIN_VALUE;
for (int year = 0; year < SUNSPOTS.length; year++) {
min = Math.min(min, SUNSPOTS[year]);
max = Math.max(max, SUNSPOTS[year]);
}
normalizedSunspots = new double[SUNSPOTS.length];
closedLoopSunspots = new double[SUNSPOTS.length];
mean = 0;
for (int year = 0; year < SUNSPOTS.length; year++) {
normalizedSunspots[year] = closedLoopSunspots[year] = ((SUNSPOTS[year] - min) / (max - min))
* (hi - lo) + lo;
mean += normalizedSunspots[year] / SUNSPOTS.length;
}
}
/**
* Generate the training data for the training sunspot years.
* @return The training data.
*/
public DataSet generateTrainingData() {
DataSet result = new DataSet(WINDOW_SIZE, 1);
for (int year = TRAIN_START; year < TRAIN_END; year++) {
double[] input = new double[WINDOW_SIZE];
double[] ideal = new double[1];
int index = 0;
for (int i = year - WINDOW_SIZE; i < year; i++) {
input[index++] = this.normalizedSunspots[i];
}
ideal[0] = this.normalizedSunspots[year];
result.addRow(new DataSetRow(input, ideal));
}
return result;
}
/**
* Predict sunspots.
* @param network Neural network to use.
*/
public void predict(NeuralNetwork network) {
NumberFormat f = NumberFormat.getNumberInstance();
f.setMaximumFractionDigits(4);
f.setMinimumFractionDigits(4);
System.out.println("Year\tActual\tPredict\tClosed Loop Predict");
for (int year = EVALUATE_START; year < EVALUATE_END; year++) {
// calculate based on actual data
double[] input = new double[WINDOW_SIZE];
for (int i = 0; i < input.length; i++) {
input[i] = this.normalizedSunspots[(year - WINDOW_SIZE) + i];
}
network.setInput(input);
network.calculate();
double[] output = network.getOutput();
double prediction = output[0];
this.closedLoopSunspots[year] = prediction;
// calculate "closed loop", based on predicted data
for (int i = 0; i < input.length; i++) {
input[i] = this.closedLoopSunspots[(year - WINDOW_SIZE) + i];
}
network.setInput(input);
network.calculate();
output = network.getOutput();
double closedLoopPrediction = output[0];
// display
System.out.println((STARTING_YEAR + year) + "\t"
+ f.format(this.normalizedSunspots[year]) + "\t"
+ f.format(prediction) + "\t"
+ f.format(closedLoopPrediction));
}
}
public void run() {
// uncomment the following line to use regular Neuroph (non-flat) processing
//Neuroph.getInstance().setFlattenNetworks(false);
// create neural network
NeuralNetwork network = new MultiLayerPerceptron(TransferFunctionType.SIGMOID, WINDOW_SIZE, 10, 1);
// normalize training data
normalizeSunspots(0.1, 0.9);
network.getLearningRule().addListener(this);
// create training set
DataSet trainingSet = generateTrainingData();
network.learn(trainingSet);
predict(network);
Neuroph.getInstance().shutdown();
}
public static void main(String args[]) {
SunSpots sunspot = new SunSpots();
sunspot.run();
}
public void handleLearningEvent(LearningEvent event) {
SupervisedLearning rule = (SupervisedLearning)event.getSource();
System.out.println( "Training, Network Epoch " + rule.getCurrentIteration() + ", Error:" + rule.getTotalNetworkError());
}
}
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