Scalar3D.java
- package org.opentrafficsim.core.math;
- import org.djunits.unit.DirectionUnit;
- import org.djunits.value.vdouble.scalar.Direction;
- /**
- * Calculate between Polar (spherical) and Cartesian (xyz) coordinates.
- * <p>
- * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
- * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
- * </p>
- * $LastChangedDate: 2015-07-24 02:58:59 +0200 (Fri, 24 Jul 2015) $, @version $Revision: 1147 $, by $Author: averbraeck $,
- * initial version Dec 11, 2015 <br>
- * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
- * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
- */
- public final class Scalar3D
- {
- /** Utility class, don't instantiate. */
- private Scalar3D()
- {
- }
- /**
- * @param r double; the radius
- * @param theta double; the angle from the z direction
- * @param phi double; the projected angle in the xy-plane from the x direction
- * @return a double array [x, y, z] with cartesian coordinates
- */
- public static double[] polarToCartesian(final double r, final double theta, final double phi)
- {
- // double x = r * Math.sin(theta) * Math.cos(phi);
- // double y = r * Math.sin(theta) * Math.sin(phi);
- // double z = r * Math.cos(theta);
- double mst = Math.sin(theta);
- double msp = Math.sin(phi);
- double mct = Math.sqrt(1.0 - mst * mst);
- double mcp = Math.sqrt(1.0 - msp * msp);
- return new double[] { r * mst * mcp, r * mst * msp, r * mct };
- }
- /**
- * Get the (polar) radius based on Cartesian coordinates.
- * @param x double; the x-coordinate
- * @param y double; the y-coordinate
- * @param z double; the z-coordinate
- * @return the radius, which is the distance from (0,0,0)
- */
- public static double cartesianToRadius(final double x, final double y, final double z)
- {
- return Math.sqrt(x * x + y * y + z * z);
- }
- /**
- * Get the (polar) theta angle, which is the angle from the z-direction, from Cartesian coordinates.
- * @param x double; the x-coordinate
- * @param y double; the y-coordinate
- * @param z double; the z-coordinate
- * @return the radius, which is the distance from (0,0,0)
- */
- public static Direction cartesianToTheta(final double x, final double y, final double z)
- {
- double r = Math.sqrt(x * x + y * y + z * z);
- return new Direction(Math.acos(z / r), DirectionUnit.NORTH_RADIAN);
- }
- /**
- * Get the (polar) phi angle, which is the projected angle in the xy-plane from the x direction.
- * @param x double; the x-coordinate
- * @param y double; the y-coordinate
- * @return the projected angle of direction in the xy-plane
- */
- public static Direction cartesianToPhi(final double x, final double y)
- {
- return new Direction(Math.atan2(y, x), DirectionUnit.NORTH_RADIAN);
- }
- }