/*
* 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.math3.optimization.univariate;
import org.apache.commons.math3.analysis.UnivariateFunction;
import org.apache.commons.math3.optimization.GoalType;
import org.junit.Assert;
import org.junit.Test;
/**
* Test for {@link BracketFinder}.
*/
@Deprecated
public class BracketFinderTest {
@Test
public void testCubicMin() {
final BracketFinder bFind = new BracketFinder();
final UnivariateFunction func = new UnivariateFunction() {
public double value(double x) {
if (x < -2) {
return value(-2);
}
else {
return (x - 1) * (x + 2) * (x + 3);
}
}
};
bFind.search(func, GoalType.MINIMIZE, -2 , -1);
final double tol = 1e-15;
// Comparing with results computed in Python.
Assert.assertEquals(-2, bFind.getLo(), tol);
Assert.assertEquals(-1, bFind.getMid(), tol);
Assert.assertEquals(0.61803399999999997, bFind.getHi(), tol);
}
@Test
public void testCubicMax() {
final BracketFinder bFind = new BracketFinder();
final UnivariateFunction func = new UnivariateFunction() {
public double value(double x) {
if (x < -2) {
return value(-2);
}
else {
return -(x - 1) * (x + 2) * (x + 3);
}
}
};
bFind.search(func, GoalType.MAXIMIZE, -2 , -1);
final double tol = 1e-15;
Assert.assertEquals(-2, bFind.getLo(), tol);
Assert.assertEquals(-1, bFind.getMid(), tol);
Assert.assertEquals(0.61803399999999997, bFind.getHi(), tol);
}
@Test
public void testMinimumIsOnIntervalBoundary() {
final UnivariateFunction func = new UnivariateFunction() {
public double value(double x) {
return x * x;
}
};
final BracketFinder bFind = new BracketFinder();
bFind.search(func, GoalType.MINIMIZE, 0, 1);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
bFind.search(func, GoalType.MINIMIZE, -1, 0);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
}
@Test
public void testIntervalBoundsOrdering() {
final UnivariateFunction func = new UnivariateFunction() {
public double value(double x) {
return x * x;
}
};
final BracketFinder bFind = new BracketFinder();
bFind.search(func, GoalType.MINIMIZE, -1, 1);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
bFind.search(func, GoalType.MINIMIZE, 1, -1);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
bFind.search(func, GoalType.MINIMIZE, 1, 2);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
bFind.search(func, GoalType.MINIMIZE, 2, 1);
Assert.assertTrue(bFind.getLo() <= 0);
Assert.assertTrue(0 <= bFind.getHi());
}
}