Java example source code file (CircleTest.java)

This example Java source code file (CircleTest.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

arc, circle, circletest, randomgenerator, rotation, s2point, sphere1d, sublimitangle, test, transform, unitsphererandomvectorgenerator, vector3d, well1024a

The CircleTest.java Java example source code

/*
 * 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.geometry.spherical.twod;

import org.apache.commons.math3.geometry.euclidean.threed.Rotation;
import org.apache.commons.math3.geometry.euclidean.threed.RotationConvention;
import org.apache.commons.math3.geometry.euclidean.threed.Vector3D;
import org.apache.commons.math3.geometry.partitioning.Transform;
import org.apache.commons.math3.geometry.spherical.oned.Arc;
import org.apache.commons.math3.geometry.spherical.oned.LimitAngle;
import org.apache.commons.math3.geometry.spherical.oned.S1Point;
import org.apache.commons.math3.geometry.spherical.oned.Sphere1D;
import org.apache.commons.math3.geometry.spherical.oned.SubLimitAngle;
import org.apache.commons.math3.random.RandomGenerator;
import org.apache.commons.math3.random.UnitSphereRandomVectorGenerator;
import org.apache.commons.math3.random.Well1024a;
import org.apache.commons.math3.util.FastMath;
import org.apache.commons.math3.util.MathUtils;
import org.junit.Assert;
import org.junit.Test;

public class CircleTest {

    @Test
    public void testEquator() {
        Circle circle = new Circle(new Vector3D(0, 0, 1000), 1.0e-10).copySelf();
        Assert.assertEquals(Vector3D.PLUS_K, circle.getPole());
        Assert.assertEquals(1.0e-10, circle.getTolerance(), 1.0e-20);
        circle.revertSelf();
        Assert.assertEquals(Vector3D.MINUS_K, circle.getPole());
        Assert.assertEquals(Vector3D.PLUS_K, circle.getReverse().getPole());
        Assert.assertEquals(Vector3D.MINUS_K, circle.getPole());
    }

    @Test
    public void testXY() {
        Circle circle = new Circle(new S2Point(1.2, 2.5), new S2Point(-4.3, 0), 1.0e-10);
        Assert.assertEquals(0.0, circle.getPointAt(0).distance(circle.getXAxis()), 1.0e-10);
        Assert.assertEquals(0.0, circle.getPointAt(0.5 * FastMath.PI).distance(circle.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(circle.getXAxis(), circle.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(circle.getXAxis(), circle.getPole()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(circle.getPole(), circle.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.0,
                            circle.getPole().distance(Vector3D.crossProduct(circle.getXAxis(), circle.getYAxis())),
                            1.0e-10);
    }

    @Test
    public void testReverse() {
        Circle circle = new Circle(new S2Point(1.2, 2.5), new S2Point(-4.3, 0), 1.0e-10);
        Circle reversed = circle.getReverse();
        Assert.assertEquals(0.0, reversed.getPointAt(0).distance(reversed.getXAxis()), 1.0e-10);
        Assert.assertEquals(0.0, reversed.getPointAt(0.5 * FastMath.PI).distance(reversed.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(reversed.getXAxis(), reversed.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(reversed.getXAxis(), reversed.getPole()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(reversed.getPole(), reversed.getYAxis()), 1.0e-10);
        Assert.assertEquals(0.0,
                            reversed.getPole().distance(Vector3D.crossProduct(reversed.getXAxis(), reversed.getYAxis())),
                            1.0e-10);

        Assert.assertEquals(0, Vector3D.angle(circle.getXAxis(), reversed.getXAxis()), 1.0e-10);
        Assert.assertEquals(FastMath.PI, Vector3D.angle(circle.getYAxis(), reversed.getYAxis()), 1.0e-10);
        Assert.assertEquals(FastMath.PI, Vector3D.angle(circle.getPole(), reversed.getPole()), 1.0e-10);

        Assert.assertTrue(circle.sameOrientationAs(circle));
        Assert.assertFalse(circle.sameOrientationAs(reversed));

    }

    @Test
    public void testPhase() {
        Circle circle = new Circle(new S2Point(1.2, 2.5), new S2Point(-4.3, 0), 1.0e-10);
        Vector3D p = new Vector3D(1, 2, -4);
        Vector3D samePhase = circle.getPointAt(circle.getPhase(p));
        Assert.assertEquals(0.0,
                            Vector3D.angle(Vector3D.crossProduct(circle.getPole(), p),
                                           Vector3D.crossProduct(circle.getPole(), samePhase)),
                            1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(circle.getPole(), samePhase), 1.0e-10);
        Assert.assertEquals(circle.getPhase(p), circle.getPhase(samePhase), 1.0e-10);
        Assert.assertEquals(0.0, circle.getPhase(circle.getXAxis()), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, circle.getPhase(circle.getYAxis()), 1.0e-10);

    }

    @Test
    public void testSubSpace() {
        Circle circle = new Circle(new S2Point(1.2, 2.5), new S2Point(-4.3, 0), 1.0e-10);
        Assert.assertEquals(0.0, circle.toSubSpace(new S2Point(circle.getXAxis())).getAlpha(), 1.0e-10);
        Assert.assertEquals(0.5 * FastMath.PI, circle.toSubSpace(new S2Point(circle.getYAxis())).getAlpha(), 1.0e-10);
        Vector3D p = new Vector3D(1, 2, -4);
        Assert.assertEquals(circle.getPhase(p), circle.toSubSpace(new S2Point(p)).getAlpha(), 1.0e-10);
    }

    @Test
    public void testSpace() {
        Circle circle = new Circle(new S2Point(1.2, 2.5), new S2Point(-4.3, 0), 1.0e-10);
        for (double alpha = 0; alpha < MathUtils.TWO_PI; alpha += 0.1) {
            Vector3D p = new Vector3D(FastMath.cos(alpha), circle.getXAxis(),
                                      FastMath.sin(alpha), circle.getYAxis());
            Vector3D q = circle.toSpace(new S1Point(alpha)).getVector();
            Assert.assertEquals(0.0, p.distance(q), 1.0e-10);
            Assert.assertEquals(0.5 * FastMath.PI, Vector3D.angle(circle.getPole(), q), 1.0e-10);
        }
    }

    @Test
    public void testOffset() {
        Circle circle = new Circle(Vector3D.PLUS_K, 1.0e-10);
        Assert.assertEquals(0.0,                circle.getOffset(new S2Point(Vector3D.PLUS_I)),  1.0e-10);
        Assert.assertEquals(0.0,                circle.getOffset(new S2Point(Vector3D.MINUS_I)), 1.0e-10);
        Assert.assertEquals(0.0,                circle.getOffset(new S2Point(Vector3D.PLUS_J)),  1.0e-10);
        Assert.assertEquals(0.0,                circle.getOffset(new S2Point(Vector3D.MINUS_J)), 1.0e-10);
        Assert.assertEquals(-0.5 * FastMath.PI, circle.getOffset(new S2Point(Vector3D.PLUS_K)),  1.0e-10);
        Assert.assertEquals( 0.5 * FastMath.PI, circle.getOffset(new S2Point(Vector3D.MINUS_K)), 1.0e-10);

    }

    @Test
    public void testInsideArc() {
        RandomGenerator random = new Well1024a(0xbfd34e92231bbcfel);
        UnitSphereRandomVectorGenerator sphRandom = new UnitSphereRandomVectorGenerator(3, random);
        for (int i = 0; i < 100; ++i) {
            Circle c1 = new Circle(new Vector3D(sphRandom.nextVector()), 1.0e-10);
            Circle c2 = new Circle(new Vector3D(sphRandom.nextVector()), 1.0e-10);
            checkArcIsInside(c1, c2);
            checkArcIsInside(c2, c1);
        }
    }

    private void checkArcIsInside(final Circle arcCircle, final Circle otherCircle) {
        Arc arc = arcCircle.getInsideArc(otherCircle);
        Assert.assertEquals(FastMath.PI, arc.getSize(), 1.0e-10);
        for (double alpha = arc.getInf(); alpha < arc.getSup(); alpha += 0.1) {
            Assert.assertTrue(otherCircle.getOffset(arcCircle.getPointAt(alpha)) <= 2.0e-15);
        }
        for (double alpha = arc.getSup(); alpha < arc.getInf() + MathUtils.TWO_PI; alpha += 0.1) {
            Assert.assertTrue(otherCircle.getOffset(arcCircle.getPointAt(alpha)) >= -2.0e-15);
        }
    }

    @Test
    public void testTransform() {
        RandomGenerator random = new Well1024a(0x16992fc4294bf2f1l);
        UnitSphereRandomVectorGenerator sphRandom = new UnitSphereRandomVectorGenerator(3, random);
        for (int i = 0; i < 100; ++i) {

            Rotation r = new Rotation(new Vector3D(sphRandom.nextVector()),
                                      FastMath.PI * random.nextDouble(),
                                      RotationConvention.VECTOR_OPERATOR);
            Transform<Sphere2D, Sphere1D> t = Circle.getTransform(r);

            S2Point  p = new S2Point(new Vector3D(sphRandom.nextVector()));
            S2Point tp = (S2Point) t.apply(p);
            Assert.assertEquals(0.0, r.applyTo(p.getVector()).distance(tp.getVector()), 1.0e-10);

            Circle  c = new Circle(new Vector3D(sphRandom.nextVector()), 1.0e-10);
            Circle tc = (Circle) t.apply(c);
            Assert.assertEquals(0.0, r.applyTo(c.getPole()).distance(tc.getPole()),   1.0e-10);
            Assert.assertEquals(0.0, r.applyTo(c.getXAxis()).distance(tc.getXAxis()), 1.0e-10);
            Assert.assertEquals(0.0, r.applyTo(c.getYAxis()).distance(tc.getYAxis()), 1.0e-10);
            Assert.assertEquals(c.getTolerance(), ((Circle) t.apply(c)).getTolerance(), 1.0e-10);

            SubLimitAngle  sub = new LimitAngle(new S1Point(MathUtils.TWO_PI * random.nextDouble()),
                                                random.nextBoolean(), 1.0e-10).wholeHyperplane();
            Vector3D psub = c.getPointAt(((LimitAngle) sub.getHyperplane()).getLocation().getAlpha());
            SubLimitAngle tsub = (SubLimitAngle) t.apply(sub, c, tc);
            Vector3D ptsub = tc.getPointAt(((LimitAngle) tsub.getHyperplane()).getLocation().getAlpha());
            Assert.assertEquals(0.0, r.applyTo(psub).distance(ptsub), 1.0e-10);

        }
    }

}