Java tutorial
/* * 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; /** * Interface representing a <a href="http://mathworld.wolfram.com/Field.html">field</a>. * <p> * Classes implementing this interface will often be singletons. * </p> * @param <T> the type of the field elements * @see FieldElement * @since 2.0 */ public interface Field<T> { /** Get the additive identity of the field. * <p> * The additive identity is the element e<sub>0</sub> of the field such that * for all elements a of the field, the equalities a + e<sub>0</sub> = * e<sub>0</sub> + a = a hold. * </p> * @return additive identity of the field */ T getZero(); /** Get the multiplicative identity of the field. * <p> * The multiplicative identity is the element e<sub>1</sub> of the field such that * for all elements a of the field, the equalities a × e<sub>1</sub> = * e<sub>1</sub> × a = a hold. * </p> * @return multiplicative identity of the field */ T getOne(); /** * Returns the runtime class of the FieldElement. * * @return The {@code Class} object that represents the runtime * class of this object. */ Class<? extends FieldElement<T>> getRuntimeClass(); }