/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.commons.math4.fitting.leastsquares;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.commons.math4.util.FastMath;
/**
* A factory to create instances of {@link StatisticalReferenceDataset} from
* available resources.
*/
public class StatisticalReferenceDatasetFactory {
private StatisticalReferenceDatasetFactory() {
// Do nothing
}
/**
* Creates a new buffered reader from the specified resource name.
*
* @param name the name of the resource
* @return a buffered reader
* @throws IOException if an I/O error occured
*/
public static BufferedReader createBufferedReaderFromResource(final String name)
throws IOException {
final InputStream resourceAsStream;
resourceAsStream = StatisticalReferenceDatasetFactory.class
.getResourceAsStream(name);
if (resourceAsStream == null) {
throw new IOException("could not find resource " + name);
}
return new BufferedReader(new InputStreamReader(resourceAsStream));
}
public static StatisticalReferenceDataset createKirby2()
throws IOException {
final BufferedReader in = createBufferedReaderFromResource("Kirby2.dat");
StatisticalReferenceDataset dataset = null;
try {
dataset = new StatisticalReferenceDataset(in) {
@Override
public double getModelValue(final double x, final double[] a) {
final double p = a[0] + x * (a[1] + x * a[2]);
final double q = 1.0 + x * (a[3] + x * a[4]);
return p / q;
}
@Override
public double[] getModelDerivatives(final double x,
final double[] a) {
final double[] dy = new double[5];
final double p = a[0] + x * (a[1] + x * a[2]);
final double q = 1.0 + x * (a[3] + x * a[4]);
dy[0] = 1.0 / q;
dy[1] = x / q;
dy[2] = x * dy[1];
dy[3] = -x * p / (q * q);
dy[4] = x * dy[3];
return dy;
}
};
} finally {
in.close();
}
return dataset;
}
public static StatisticalReferenceDataset createHahn1()
throws IOException {
final BufferedReader in = createBufferedReaderFromResource("Hahn1.dat");
StatisticalReferenceDataset dataset = null;
try {
dataset = new StatisticalReferenceDataset(in) {
@Override
public double getModelValue(final double x, final double[] a) {
final double p = a[0] + x * (a[1] + x * (a[2] + x * a[3]));
final double q = 1.0 + x * (a[4] + x * (a[5] + x * a[6]));
return p / q;
}
@Override
public double[] getModelDerivatives(final double x,
final double[] a) {
final double[] dy = new double[7];
final double p = a[0] + x * (a[1] + x * (a[2] + x * a[3]));
final double q = 1.0 + x * (a[4] + x * (a[5] + x * a[6]));
dy[0] = 1.0 / q;
dy[1] = x * dy[0];
dy[2] = x * dy[1];
dy[3] = x * dy[2];
dy[4] = -x * p / (q * q);
dy[5] = x * dy[4];
dy[6] = x * dy[5];
return dy;
}
};
} finally {
in.close();
}
return dataset;
}
public static StatisticalReferenceDataset createMGH17()
throws IOException {
final BufferedReader in = createBufferedReaderFromResource("MGH17.dat");
StatisticalReferenceDataset dataset = null;
try {
dataset = new StatisticalReferenceDataset(in) {
@Override
public double getModelValue(final double x, final double[] a) {
return a[0] + a[1] * FastMath.exp(-a[3] * x) + a[2] *
FastMath.exp(-a[4] * x);
}
@Override
public double[] getModelDerivatives(final double x,
final double[] a) {
final double[] dy = new double[5];
dy[0] = 1.0;
dy[1] = FastMath.exp(-x * a[3]);
dy[2] = FastMath.exp(-x * a[4]);
dy[3] = -x * a[1] * dy[1];
dy[4] = -x * a[2] * dy[2];
return dy;
}
};
} finally {
in.close();
}
return dataset;
}
public static StatisticalReferenceDataset createLanczos1()
throws IOException {
final BufferedReader in =
createBufferedReaderFromResource("Lanczos1.dat");
StatisticalReferenceDataset dataset = null;
try {
dataset = new StatisticalReferenceDataset(in) {
@Override
public double getModelValue(final double x, final double[] a) {
System.out.println(a[0]+", "+a[1]+", "+a[2]+", "+a[3]+", "+a[4]+", "+a[5]);
return a[0] * FastMath.exp(-a[3] * x) +
a[1] * FastMath.exp(-a[4] * x) +
a[2] * FastMath.exp(-a[5] * x);
}
@Override
public double[] getModelDerivatives(final double x,
final double[] a) {
final double[] dy = new double[6];
dy[0] = FastMath.exp(-x * a[3]);
dy[1] = FastMath.exp(-x * a[4]);
dy[2] = FastMath.exp(-x * a[5]);
dy[3] = -x * a[0] * dy[0];
dy[4] = -x * a[1] * dy[1];
dy[5] = -x * a[2] * dy[2];
return dy;
}
};
} finally {
in.close();
}
return dataset;
}
/**
* Returns an array with all available reference datasets.
*
* @return the array of datasets
* @throws IOException if an I/O error occurs
*/
public StatisticalReferenceDataset[] createAll()
throws IOException {
return new StatisticalReferenceDataset[] {
createKirby2(), createMGH17()
};
}
}