    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     * <code>log(1 + p)</code> function.
    029     *
    030     * @since 3.0
    031     * @version $Id: Log1p.java 1383441 2012-09-11 14:56:39Z luc $
    032     */
    033    public class Log1p implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction {
    034        /** {@inheritDoc} */
    035        public double value(double x) {
    036            return FastMath.log1p(x);
    037        }
    038
    039        /** {@inheritDoc}
    040         * @deprecated as of 3.1, replaced by {@link #value(DerivativeStructure)}
    041         */
    042        @Deprecated
    043        public UnivariateFunction derivative() {
    044            return FunctionUtils.toDifferentiableUnivariateFunction(this).derivative();
    045        }
    046
    047        /** {@inheritDoc}
    048         * @since 3.1
    049         */
    050        public DerivativeStructure value(final DerivativeStructure t) {
    051            return t.log1p();
    052        }
    053
    054    }