001/*
002 * Units of Measurement API
003 * Copyright (c) 2014-2015, Jean-Marie Dautelle, Werner Keil, V2COM.
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-363 nor the names of its contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package javax.measure;
031
032import java.util.Map;
033
034/**
035 * Represents the dimension of a unit.
036 *
037 * <p>Concrete dimensions are obtained through the {@link Unit#getDimension()} method.</p>
038 *
039 * <p>Two units {@code u1} and {@code u2} are {@linkplain Unit#isCompatible(Unit) compatible}
040 * if and only if {@code u1.getDimension().equals(u2.getDimension())}.</p>
041 *
042 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
043 * @author <a href="mailto:units@catmedia.us">Werner Keil</a>
044 * @version 0.13, December 6, 2014
045 *
046 * @see <a href="http://en.wikipedia.org/wiki/Dimensional_analysis">Wikipedia: Dimensional Analysis</a>
047 */
048public interface Dimension {
049    /**
050     * Returns the product of this dimension with the one specified.
051     *
052     * @param  multiplicand the dimension multiplicand.
053     * @return {@code this * multiplicand}
054     */
055    Dimension multiply(Dimension multiplicand);
056
057    /**
058     * Returns the quotient of this dimension with the one specified.
059     *
060     * @param  divisor the dimension divisor.
061     * @return {@code this / divisor}
062     */
063    Dimension divide(Dimension divisor);
064
065    /**
066     * Returns this dimension raised to an exponent.
067     * <tt>(this<sup>n</sup>)</tt>
068     *
069     * @param  n power to raise this {@code Dimension} to.
070     * @return <tt>this<sup>n</sup></tt>
071     */
072    Dimension pow(int n);
073
074    /**
075     * Returns the given root of this dimension.
076     *
077     * @param  n the root's order.
078     * @return the result of taking the given root of this dimension.
079     * @throws ArithmeticException if {@code n == 0}.
080     */
081    Dimension root(int n);
082
083    /**
084     * Returns the fundamental dimensions and their exponent whose product is
085     * this dimension, or {@code null} if this dimension is a fundamental dimension.
086     *
087     * @return the mapping between the fundamental dimensions and their exponent.
088     */
089    Map<? extends Dimension, Integer> getProductDimensions();
090}