001/* An actor that converts a complex token to polar coordinates.
002
003 Copyright (c) 1998-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026
027 */
028package ptolemy.actor.lib.conversions;
029
030import ptolemy.actor.TypedAtomicActor;
031import ptolemy.actor.TypedIOPort;
032import ptolemy.data.ComplexToken;
033import ptolemy.data.DoubleToken;
034import ptolemy.data.type.BaseType;
035import ptolemy.kernel.CompositeEntity;
036import ptolemy.kernel.util.IllegalActionException;
037import ptolemy.kernel.util.NameDuplicationException;
038import ptolemy.math.Complex;
039
040///////////////////////////////////////////////////////////////////
041/// ComplexToPolar
042
043/**
044 <p>Convert a complex token to polar coordinates, which are represented by two
045 double tokens (magnitude and angle).  The output angle is in radians.</p>
046 <p>
047 The implementation uses java.lang.Math.atan2(double, double).
048 </p>
049
050 @see java.lang.Math#atan2(double, double)
051
052 @author Michael Leung, Edward A. Lee, and Paul Whitaker
053 @version $Id$
054 @since Ptolemy II 1.0
055 @Pt.ProposedRating Green (pwhitake)
056 @Pt.AcceptedRating Green (cxh)
057 */
058public class ComplexToPolar extends TypedAtomicActor {
059    /** Construct an actor with the given container and name.
060     *  @param container The container.
061     *  @param name The name of this actor.
062     *  @exception IllegalActionException If the actor cannot be contained
063     *   by the proposed container.
064     *  @exception NameDuplicationException If the container already has an
065     *   actor with this name.
066     */
067    public ComplexToPolar(CompositeEntity container, String name)
068            throws NameDuplicationException, IllegalActionException {
069        super(container, name);
070
071        input = new TypedIOPort(this, "input", true, false);
072        input.setTypeEquals(BaseType.COMPLEX);
073
074        magnitude = new TypedIOPort(this, "magnitude", false, true);
075        magnitude.setTypeEquals(BaseType.DOUBLE);
076
077        angle = new TypedIOPort(this, "angle", false, true);
078        angle.setTypeEquals(BaseType.DOUBLE);
079
080        _attachText("_iconDescription",
081                "<svg>\n" + "<polygon points=\"-15,-15 15,15 15,-15 -15,15\" "
082                        + "style=\"fill:white\"/>\n" + "</svg>\n");
083    }
084
085    ///////////////////////////////////////////////////////////////////
086    ////                         public variables                  ////
087
088    /** The port for the input, which has type ComplexToken. */
089    public TypedIOPort input;
090
091    /** The output port for the magnitude component, which has type
092     DoubleToken. */
093    public TypedIOPort magnitude;
094
095    /** The output port for the angle component, which has type DoubleToken. */
096    public TypedIOPort angle;
097
098    ///////////////////////////////////////////////////////////////////
099    ////                         public methods                    ////
100
101    /** Consume one complex token on the input port and output a new double
102     *  token on each of the two output ports (magnitude and angle). The
103     *  outputs are a polar form representation of the complex input. The
104     *  output angle is in radians.
105     *
106     *  @exception IllegalActionException If there is no director.
107     */
108    @Override
109    public void fire() throws IllegalActionException {
110        super.fire();
111        Complex inputValue = ((ComplexToken) input.get(0)).complexValue();
112
113        double magnitudeValue = Math.sqrt(inputValue.real * inputValue.real
114                + inputValue.imag * inputValue.imag);
115
116        double angleValue = Math.atan2(inputValue.imag, inputValue.real);
117
118        magnitude.send(0, new DoubleToken(magnitudeValue));
119        angle.send(0, new DoubleToken(angleValue));
120    }
121
122    /** Return false if the input port has no token, otherwise return
123     *  what the superclass returns (presumably true).
124     *  @exception IllegalActionException If there is no director.
125     */
126    @Override
127    public boolean prefire() throws IllegalActionException {
128        if (!input.hasToken(0)) {
129            return false;
130        }
131
132        return super.prefire();
133    }
134}