/*
* 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.
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package org.apache.commons.math4.geometry.euclidean.twod;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.apache.commons.math4.geometry.enclosing.EnclosingBall;
import org.apache.commons.math4.geometry.euclidean.twod.DiskGenerator;
import org.apache.commons.math4.geometry.euclidean.twod.Euclidean2D;
import org.apache.commons.math4.geometry.euclidean.twod.Cartesian2D;
import org.apache.commons.math4.random.UnitSphereRandomVectorGenerator;
import org.apache.commons.rng.UniformRandomProvider;
import org.apache.commons.rng.simple.RandomSource;
import org.junit.Assert;
import org.junit.Test;
public class DiskGeneratorTest {
@Test
public void testSupport0Point() {
List<Cartesian2D> support = Arrays.asList(new Cartesian2D[0]);
EnclosingBall<Euclidean2D, Cartesian2D> disk = new DiskGenerator().ballOnSupport(support);
Assert.assertTrue(disk.getRadius() < 0);
Assert.assertEquals(0, disk.getSupportSize());
Assert.assertEquals(0, disk.getSupport().length);
}
@Test
public void testSupport1Point() {
List<Cartesian2D> support = Arrays.asList(new Cartesian2D(1, 2));
EnclosingBall<Euclidean2D, Cartesian2D> disk = new DiskGenerator().ballOnSupport(support);
Assert.assertEquals(0.0, disk.getRadius(), 1.0e-10);
Assert.assertTrue(disk.contains(support.get(0)));
Assert.assertTrue(disk.contains(support.get(0), 0.5));
Assert.assertFalse(disk.contains(new Cartesian2D(support.get(0).getX() + 0.1,
support.get(0).getY() - 0.1),
0.001));
Assert.assertTrue(disk.contains(new Cartesian2D(support.get(0).getX() + 0.1,
support.get(0).getY() - 0.1),
0.5));
Assert.assertEquals(0, support.get(0).distance(disk.getCenter()), 1.0e-10);
Assert.assertEquals(1, disk.getSupportSize());
Assert.assertTrue(support.get(0) == disk.getSupport()[0]);
}
@Test
public void testSupport2Points() {
List<Cartesian2D> support = Arrays.asList(new Cartesian2D(1, 0),
new Cartesian2D(3, 0));
EnclosingBall<Euclidean2D, Cartesian2D> disk = new DiskGenerator().ballOnSupport(support);
Assert.assertEquals(1.0, disk.getRadius(), 1.0e-10);
int i = 0;
for (Cartesian2D v : support) {
Assert.assertTrue(disk.contains(v));
Assert.assertEquals(1.0, v.distance(disk.getCenter()), 1.0e-10);
Assert.assertTrue(v == disk.getSupport()[i++]);
}
Assert.assertTrue(disk.contains(new Cartesian2D(2, 0.9)));
Assert.assertFalse(disk.contains(Cartesian2D.ZERO));
Assert.assertEquals(0.0, new Cartesian2D(2, 0).distance(disk.getCenter()), 1.0e-10);
Assert.assertEquals(2, disk.getSupportSize());
}
@Test
public void testSupport3Points() {
List<Cartesian2D> support = Arrays.asList(new Cartesian2D(1, 0),
new Cartesian2D(3, 0),
new Cartesian2D(2, 2));
EnclosingBall<Euclidean2D, Cartesian2D> disk = new DiskGenerator().ballOnSupport(support);
Assert.assertEquals(5.0 / 4.0, disk.getRadius(), 1.0e-10);
int i = 0;
for (Cartesian2D v : support) {
Assert.assertTrue(disk.contains(v));
Assert.assertEquals(5.0 / 4.0, v.distance(disk.getCenter()), 1.0e-10);
Assert.assertTrue(v == disk.getSupport()[i++]);
}
Assert.assertTrue(disk.contains(new Cartesian2D(2, 0.9)));
Assert.assertFalse(disk.contains(new Cartesian2D(0.9, 0)));
Assert.assertFalse(disk.contains(new Cartesian2D(3.1, 0)));
Assert.assertTrue(disk.contains(new Cartesian2D(2.0, -0.499)));
Assert.assertFalse(disk.contains(new Cartesian2D(2.0, -0.501)));
Assert.assertEquals(0.0, new Cartesian2D(2.0, 3.0 / 4.0).distance(disk.getCenter()), 1.0e-10);
Assert.assertEquals(3, disk.getSupportSize());
}
@Test
public void testRandom() {
final UniformRandomProvider random = RandomSource.create(RandomSource.WELL_1024_A,
0x12faa818373ffe90l);
final UnitSphereRandomVectorGenerator sr = new UnitSphereRandomVectorGenerator(2, random);
for (int i = 0; i < 500; ++i) {
double d = 25 * random.nextDouble();
double refRadius = 10 * random.nextDouble();
Cartesian2D refCenter = new Cartesian2D(d, new Cartesian2D(sr.nextVector()));
List<Cartesian2D> support = new ArrayList<>();
for (int j = 0; j < 3; ++j) {
support.add(new Cartesian2D(1.0, refCenter, refRadius, new Cartesian2D(sr.nextVector())));
}
EnclosingBall<Euclidean2D, Cartesian2D> disk = new DiskGenerator().ballOnSupport(support);
Assert.assertEquals(0.0, refCenter.distance(disk.getCenter()), 3e-9 * refRadius);
Assert.assertEquals(refRadius, disk.getRadius(), 7e-10 * refRadius);
}
}
}