001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.math3;
018    
019    import org.apache.commons.math3.exception.MathArithmeticException;
020    import org.apache.commons.math3.exception.NullArgumentException;
021    
022    
023    /**
024     * Interface representing <a href="http://mathworld.wolfram.com/Field.html">field</a> elements.
025     * @param <T> the type of the field elements
026     * @see Field
027     * @version $Id: FieldElement.java 1416643 2012-12-03 19:37:14Z tn $
028     * @since 2.0
029     */
030    public interface FieldElement<T> {
031    
032        /** Compute this + a.
033         * @param a element to add
034         * @return a new element representing this + a
035         * @throws NullArgumentException if {@code addend} is {@code null}.
036         */
037        T add(T a) throws NullArgumentException;
038    
039        /** Compute this - a.
040         * @param a element to subtract
041         * @return a new element representing this - a
042         * @throws NullArgumentException if {@code a} is {@code null}.
043         */
044        T subtract(T a) throws NullArgumentException;
045    
046        /**
047         * Returns the additive inverse of {@code this} element.
048         * @return the opposite of {@code this}.
049         */
050        T negate();
051    
052        /** Compute n &times; this. Multiplication by an integer number is defined
053         * as the following sum
054         * <center>
055         * n &times; this = &sum;<sub>i=1</sub><sup>n</sup> this.
056         * </center>
057         * @param n Number of times {@code this} must be added to itself.
058         * @return A new element representing n &times; this.
059         */
060        T multiply(int n);
061    
062        /** Compute this &times; a.
063         * @param a element to multiply
064         * @return a new element representing this &times; a
065         * @throws NullArgumentException if {@code a} is {@code null}.
066         */
067        T multiply(T a) throws NullArgumentException;
068    
069        /** Compute this &divide; a.
070         * @param a element to add
071         * @return a new element representing this &divide; a
072         * @throws NullArgumentException if {@code a} is {@code null}.
073         * @throws MathArithmeticException if {@code a} is zero
074         */
075        T divide(T a) throws NullArgumentException, MathArithmeticException;
076    
077        /**
078         * Returns the multiplicative inverse of {@code this} element.
079         * @return the inverse of {@code this}.
080         * @throws MathArithmeticException if {@code this} is zero
081         */
082        T reciprocal() throws MathArithmeticException;
083    
084        /** Get the {@link Field} to which the instance belongs.
085         * @return {@link Field} to which the instance belongs
086         */
087        Field<T> getField();
088    }