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 */ 017 018 package org.apache.commons.math3.analysis.function; 019 020 import org.apache.commons.math3.analysis.FunctionUtils; 021 import org.apache.commons.math3.analysis.UnivariateFunction; 022 import org.apache.commons.math3.analysis.DifferentiableUnivariateFunction; 023 import org.apache.commons.math3.analysis.differentiation.DerivativeStructure; 024 import org.apache.commons.math3.analysis.differentiation.UnivariateDifferentiableFunction; 025 import org.apache.commons.math3.util.FastMath; 026 027 /** 028 * Power function. 029 * 030 * @since 3.0 031 * @version $Id: Power.java 1383441 2012-09-11 14:56:39Z luc $ 032 */ 033 public class Power implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction { 034 /** Power. */ 035 private final double p; 036 037 /** 038 * @param p Power. 039 */ 040 public Power(double p) { 041 this.p = p; 042 } 043 044 /** {@inheritDoc} */ 045 public double value(double x) { 046 return FastMath.pow(x, p); 047 } 048 049 /** {@inheritDoc} 050 * @deprecated as of 3.1, replaced by {@link #value(DerivativeStructure)} 051 */ 052 @Deprecated 053 public UnivariateFunction derivative() { 054 return FunctionUtils.toDifferentiableUnivariateFunction(this).derivative(); 055 } 056 057 /** {@inheritDoc} 058 * @since 3.1 059 */ 060 public DerivativeStructure value(final DerivativeStructure t) { 061 return t.pow(p); 062 } 063 064 }