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.DifferentiableUnivariateFunction;
021    import org.apache.commons.math3.analysis.differentiation.DerivativeStructure;
022    import org.apache.commons.math3.analysis.differentiation.UnivariateDifferentiableFunction;
023    import org.apache.commons.math3.util.FastMath;
024    
025    /**
026     * Hyperbolic cosine function.
027     *
028     * @since 3.0
029     * @version $Id: Cosh.java 1424087 2012-12-19 20:32:50Z luc $
030     */
031    public class Cosh implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction {
032        /** {@inheritDoc} */
033        public double value(double x) {
034            return FastMath.cosh(x);
035        }
036    
037        /** {@inheritDoc}
038         * @deprecated as of 3.1, replaced by {@link #value(DerivativeStructure)}
039         */
040        @Deprecated
041        public DifferentiableUnivariateFunction derivative() {
042            return new Sinh();
043        }
044    
045        /** {@inheritDoc}
046         * @since 3.1
047         */
048        public DerivativeStructure value(final DerivativeStructure t) {
049            return t.cosh();
050        }
051    
052    }