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 018package org.apache.commons.math3.analysis.function; 019 020import org.apache.commons.math3.analysis.UnivariateFunction; 021import org.apache.commons.math3.util.FastMath; 022 023/** 024 * {@code signum} function. 025 * 026 * @since 3.0 027 */ 028public class Signum implements UnivariateFunction { 029 /** {@inheritDoc} */ 030 public double value(double x) { 031 return FastMath.signum(x); 032 } 033}