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* 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.threed;
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.threed.Euclidean3D;
import org.apache.commons.math4.geometry.euclidean.threed.SphereGenerator;
import org.apache.commons.math4.geometry.euclidean.threed.Cartesian3D;
import org.apache.commons.math4.random.UnitSphereRandomVectorGenerator;
import org.apache.commons.rng.UniformRandomProvider;
import org.apache.commons.rng.simple.RandomSource;
import org.apache.commons.math4.util.FastMath;
import org.junit.Assert;
import org.junit.Test;
public class SphereGeneratorTest {
@Test
public void testSupport0Point() {
List<Cartesian3D> support = Arrays.asList(new Cartesian3D[0]);
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertTrue(sphere.getRadius() < 0);
Assert.assertEquals(0, sphere.getSupportSize());
Assert.assertEquals(0, sphere.getSupport().length);
}
@Test
public void testSupport1Point() {
List<Cartesian3D> support = Arrays.asList(new Cartesian3D(1, 2, 3));
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertEquals(0.0, sphere.getRadius(), 1.0e-10);
Assert.assertTrue(sphere.contains(support.get(0)));
Assert.assertTrue(sphere.contains(support.get(0), 0.5));
Assert.assertFalse(sphere.contains(new Cartesian3D(support.get(0).getX() + 0.1,
support.get(0).getY() + 0.1,
support.get(0).getZ() + 0.1),
0.001));
Assert.assertTrue(sphere.contains(new Cartesian3D(support.get(0).getX() + 0.1,
support.get(0).getY() + 0.1,
support.get(0).getZ() + 0.1),
0.5));
Assert.assertEquals(0, support.get(0).distance(sphere.getCenter()), 1.0e-10);
Assert.assertEquals(1, sphere.getSupportSize());
Assert.assertTrue(support.get(0) == sphere.getSupport()[0]);
}
@Test
public void testSupport2Points() {
List<Cartesian3D> support = Arrays.asList(new Cartesian3D(1, 0, 0),
new Cartesian3D(3, 0, 0));
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertEquals(1.0, sphere.getRadius(), 1.0e-10);
int i = 0;
for (Cartesian3D v : support) {
Assert.assertTrue(sphere.contains(v));
Assert.assertEquals(1.0, v.distance(sphere.getCenter()), 1.0e-10);
Assert.assertTrue(v == sphere.getSupport()[i++]);
}
Assert.assertTrue(sphere.contains(new Cartesian3D(2, 0.9, 0)));
Assert.assertFalse(sphere.contains(Cartesian3D.ZERO));
Assert.assertEquals(0.0, new Cartesian3D(2, 0, 0).distance(sphere.getCenter()), 1.0e-10);
Assert.assertEquals(2, sphere.getSupportSize());
}
@Test
public void testSupport3Points() {
List<Cartesian3D> support = Arrays.asList(new Cartesian3D(1, 0, 0),
new Cartesian3D(3, 0, 0),
new Cartesian3D(2, 2, 0));
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertEquals(5.0 / 4.0, sphere.getRadius(), 1.0e-10);
int i = 0;
for (Cartesian3D v : support) {
Assert.assertTrue(sphere.contains(v));
Assert.assertEquals(5.0 / 4.0, v.distance(sphere.getCenter()), 1.0e-10);
Assert.assertTrue(v == sphere.getSupport()[i++]);
}
Assert.assertTrue(sphere.contains(new Cartesian3D(2, 0.9, 0)));
Assert.assertFalse(sphere.contains(new Cartesian3D(0.9, 0, 0)));
Assert.assertFalse(sphere.contains(new Cartesian3D(3.1, 0, 0)));
Assert.assertTrue(sphere.contains(new Cartesian3D(2.0, -0.499, 0)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2.0, -0.501, 0)));
Assert.assertTrue(sphere.contains(new Cartesian3D(2.0, 3.0 / 4.0, -1.249)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2.0, 3.0 / 4.0, -1.251)));
Assert.assertEquals(0.0, new Cartesian3D(2.0, 3.0 / 4.0, 0).distance(sphere.getCenter()), 1.0e-10);
Assert.assertEquals(3, sphere.getSupportSize());
}
@Test
public void testSupport4Points() {
List<Cartesian3D> support = Arrays.asList(new Cartesian3D(17, 14, 18),
new Cartesian3D(11, 14, 22),
new Cartesian3D( 2, 22, 17),
new Cartesian3D(22, 11, -10));
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertEquals(25.0, sphere.getRadius(), 1.0e-10);
int i = 0;
for (Cartesian3D v : support) {
Assert.assertTrue(sphere.contains(v));
Assert.assertEquals(25.0, v.distance(sphere.getCenter()), 1.0e-10);
Assert.assertTrue(v == sphere.getSupport()[i++]);
}
Assert.assertTrue(sphere.contains (new Cartesian3D(-22.999, 2, 2)));
Assert.assertFalse(sphere.contains(new Cartesian3D(-23.001, 2, 2)));
Assert.assertTrue(sphere.contains (new Cartesian3D( 26.999, 2, 2)));
Assert.assertFalse(sphere.contains(new Cartesian3D( 27.001, 2, 2)));
Assert.assertTrue(sphere.contains (new Cartesian3D(2, -22.999, 2)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2, -23.001, 2)));
Assert.assertTrue(sphere.contains (new Cartesian3D(2, 26.999, 2)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2, 27.001, 2)));
Assert.assertTrue(sphere.contains (new Cartesian3D(2, 2, -22.999)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2, 2, -23.001)));
Assert.assertTrue(sphere.contains (new Cartesian3D(2, 2, 26.999)));
Assert.assertFalse(sphere.contains(new Cartesian3D(2, 2, 27.001)));
Assert.assertEquals(0.0, new Cartesian3D(2.0, 2.0, 2.0).distance(sphere.getCenter()), 1.0e-10);
Assert.assertEquals(4, sphere.getSupportSize());
}
@Test
public void testRandom() {
final UniformRandomProvider random = RandomSource.create(RandomSource.WELL_1024_A,
0xd015982e9f31ee04l);
final UnitSphereRandomVectorGenerator sr = new UnitSphereRandomVectorGenerator(3, random);
for (int i = 0; i < 100; ++i) {
double d = 25 * random.nextDouble();
double refRadius = 10 * random.nextDouble();
Cartesian3D refCenter = new Cartesian3D(d, new Cartesian3D(sr.nextVector()));
List<Cartesian3D> support = new ArrayList<>();
for (int j = 0; j < 5; ++j) {
support.add(new Cartesian3D(1.0, refCenter, refRadius, new Cartesian3D(sr.nextVector())));
}
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
Assert.assertEquals(0.0, refCenter.distance(sphere.getCenter()), 4e-7 * refRadius);
Assert.assertEquals(refRadius, sphere.getRadius(), 1e-7 * refRadius);
}
}
@Test
public void testDegeneratedCase() {
final List<Cartesian3D> support =
Arrays.asList(new Cartesian3D(FastMath.scalb(-8039905610797991.0, -50), // -7.140870659936730
FastMath.scalb(-4663475464714142.0, -48), // -16.567993074240455
FastMath.scalb( 6592658872616184.0, -49)), // 11.710914678204503
new Cartesian3D(FastMath.scalb(-8036658568968473.0, -50), // -7.137986707455888
FastMath.scalb(-4664256346424880.0, -48), // -16.570767323375720
FastMath.scalb( 6591357011730307.0, -49)), // 11.708602108715928)
new Cartesian3D(FastMath.scalb(-8037820142977230.0, -50), // -7.139018392423351
FastMath.scalb(-4665280434237813.0, -48), // -16.574405614157020
FastMath.scalb( 6592435966112099.0, -49)), // 11.710518716711425
new Cartesian3D(FastMath.scalb(-8038007803611611.0, -50), // -7.139185068549035
FastMath.scalb(-4664291215918380.0, -48), // -16.570891204702250
FastMath.scalb( 6595270610894208.0, -49))); // 11.715554057357394
EnclosingBall<Euclidean3D, Cartesian3D> sphere = new SphereGenerator().ballOnSupport(support);
// the following values have been computed using Emacs calc with exact arithmetic from the
// rational representation corresponding to the scalb calls (i.e. -8039905610797991/2^50, ...)
// The results were converted to decimal representation rounded to 1.0e-30 when writing the reference
// values in this test
Assert.assertEquals( 0.003616820213530053297575846168, sphere.getRadius(), 1.0e-20);
Assert.assertEquals( -7.139325643360503322823511839511, sphere.getCenter().getX(), 1.0e-20);
Assert.assertEquals(-16.571096474251747245361467833760, sphere.getCenter().getY(), 1.0e-20);
Assert.assertEquals( 11.711945804096960876521111630800, sphere.getCenter().getZ(), 1.0e-20);
for (Cartesian3D v : support) {
Assert.assertTrue(sphere.contains(v, 1.0e-14));
}
}
}