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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.enclosing;
import java.io.IOException;
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.enclosing.WelzlEncloser;
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.junit.Assert;
import org.junit.Test;
public class WelzlEncloser3DTest {
@Test
public void testNullList() {
SphereGenerator generator = new SphereGenerator();
WelzlEncloser<Euclidean3D, Cartesian3D> encloser =
new WelzlEncloser<>(1.0e-10, generator);
EnclosingBall<Euclidean3D, Cartesian3D> ball = encloser.enclose(null);
Assert.assertTrue(ball.getRadius() < 0);
}
@Test
public void testNoPoints() {
SphereGenerator generator = new SphereGenerator();
WelzlEncloser<Euclidean3D, Cartesian3D> encloser =
new WelzlEncloser<>(1.0e-10, generator);
EnclosingBall<Euclidean3D, Cartesian3D> ball = encloser.enclose(new ArrayList<Cartesian3D>());
Assert.assertTrue(ball.getRadius() < 0);
}
@Test
public void testReducingBall() {
List<Cartesian3D> list =
Arrays.asList(new Cartesian3D(-7.140397329568118, -16.571661242582177, 11.714458961735405),
new Cartesian3D(-7.137986707455888, -16.570767323375720, 11.708602108715928),
new Cartesian3D(-7.139185068549035, -16.570891204702250, 11.715554057357394),
new Cartesian3D(-7.142682716997507, -16.571609818234290, 11.710787934580328),
new Cartesian3D(-7.139018392423351, -16.574405614157020, 11.710518716711425),
new Cartesian3D(-7.140870659936730, -16.567993074240455, 11.710914678204503),
new Cartesian3D(-7.136350173659562, -16.570498228820930, 11.713965225900928),
new Cartesian3D(-7.141675762759172, -16.572852471407028, 11.714033471449508),
new Cartesian3D(-7.140453077221105, -16.570212820780647, 11.708624578004980),
new Cartesian3D(-7.140322188726825, -16.574152894557717, 11.710305611121410),
new Cartesian3D(-7.141116131477088, -16.574061164624560, 11.712938509321699));
WelzlEncloser<Euclidean3D, Cartesian3D> encloser =
new WelzlEncloser<>(1.0e-10, new SphereGenerator());
EnclosingBall<Euclidean3D, Cartesian3D> ball = encloser.enclose(list);
Assert.assertTrue(ball.getRadius() > 0);
}
@Test
public void testInfiniteLoop() {
// this test used to generate an infinite loop
List<Cartesian3D> list =
Arrays.asList(new Cartesian3D( -0.89227075512164380, -2.89317694645713900, 14.84572323743355500),
new Cartesian3D( -0.92099498940693580, -2.31086108263908940, 12.92071026467688300),
new Cartesian3D( -0.85227999411005200, -3.06314731441320730, 15.40163831651287000),
new Cartesian3D( -1.77399413020785970, -3.65630391378114260, 14.13190097751873400),
new Cartesian3D( 0.33157833272465354, -2.22813591757792160, 14.21225234159008200),
new Cartesian3D( -1.53065579165484400, -1.65692084770139570, 14.61483055714788500),
new Cartesian3D( -1.08457093941217140, -1.96100325935602980, 13.09265170575555000),
new Cartesian3D( 0.30029469589708850, -3.05470831395667370, 14.56352400426342600),
new Cartesian3D( -0.95007443938638460, -1.86810946486118360, 15.14491234340057000),
new Cartesian3D( -1.89661503804130830, -2.17004080885185860, 14.81235128513927000),
new Cartesian3D( -0.72193328761607530, -1.44513142833618270, 14.52355724218561800),
new Cartesian3D( -0.26895980939606550, -3.69512371522084140, 14.72272846327652000),
new Cartesian3D( -1.53501693431786170, -3.25055166611021900, 15.15509062584274800),
new Cartesian3D( -0.71727553535519410, -3.62284279460799100, 13.26256700929380700),
new Cartesian3D( -0.30220950676137365, -3.25410412500779070, 13.13682612771606000),
new Cartesian3D( -0.04543996608267075, -1.93081853923797750, 14.79497997883171400),
new Cartesian3D( -1.53348892951571640, -3.66688919703524900, 14.73095600812074200),
new Cartesian3D( -0.98034899533935820, -3.34004481162763960, 13.03245014017556800));
WelzlEncloser<Euclidean3D, Cartesian3D> encloser =
new WelzlEncloser<>(1.0e-10, new SphereGenerator());
EnclosingBall<Euclidean3D, Cartesian3D> ball = encloser.enclose(list);
Assert.assertTrue(ball.getRadius() > 0);
}
@Test
public void testLargeSamples() throws IOException {
final UniformRandomProvider random = RandomSource.create(RandomSource.WELL_1024_A,
0x35ddecfc78131e1dl);
final UnitSphereRandomVectorGenerator sr = new UnitSphereRandomVectorGenerator(3, random);
for (int k = 0; k < 50; ++k) {
// define the reference sphere we want to compute
double d = 25 * random.nextDouble();
double refRadius = 10 * random.nextDouble();
Cartesian3D refCenter = new Cartesian3D(d, new Cartesian3D(sr.nextVector()));
// set up a large sample inside the reference sphere
int nbPoints = random.nextInt(1000);
List<Cartesian3D> points = new ArrayList<>();
for (int i = 0; i < nbPoints; ++i) {
double r = refRadius * random.nextDouble();
points.add(new Cartesian3D(1.0, refCenter, r, new Cartesian3D(sr.nextVector())));
}
// test we find a sphere at most as large as the one used for random drawings
checkSphere(points, refRadius);
}
}
private void checkSphere(List<Cartesian3D> points, double refRadius) {
EnclosingBall<Euclidean3D, Cartesian3D> sphere = checkSphere(points);
// compare computed sphere with bounding sphere
Assert.assertTrue(sphere.getRadius() <= refRadius);
// check removing any point of the support Sphere fails to enclose the point
for (int i = 0; i < sphere.getSupportSize(); ++i) {
List<Cartesian3D> reducedSupport = new ArrayList<>();
int count = 0;
for (Cartesian3D s : sphere.getSupport()) {
if (count++ != i) {
reducedSupport.add(s);
}
}
EnclosingBall<Euclidean3D, Cartesian3D> reducedSphere =
new SphereGenerator().ballOnSupport(reducedSupport);
boolean foundOutside = false;
for (int j = 0; j < points.size() && !foundOutside; ++j) {
if (!reducedSphere.contains(points.get(j), 1.0e-10)) {
foundOutside = true;
}
}
Assert.assertTrue(foundOutside);
}
}
private EnclosingBall<Euclidean3D, Cartesian3D> checkSphere(List<Cartesian3D> points) {
WelzlEncloser<Euclidean3D, Cartesian3D> encloser =
new WelzlEncloser<>(1.0e-10, new SphereGenerator());
EnclosingBall<Euclidean3D, Cartesian3D> Sphere = encloser.enclose(points);
// all points are enclosed
for (Cartesian3D v : points) {
Assert.assertTrue(Sphere.contains(v, 1.0e-10));
}
for (Cartesian3D v : points) {
boolean inSupport = false;
for (Cartesian3D s : Sphere.getSupport()) {
if (v == s) {
inSupport = true;
}
}
if (inSupport) {
// points on the support should be outside of reduced ball
Assert.assertFalse(Sphere.contains(v, -0.001));
}
}
return Sphere;
}
}