    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;
    019
    020    /**
    021     * Extension of {@link MultivariateFunction} representing a differentiable
    022     * multivariate real function.
    023     * @version $Id: DifferentiableMultivariateFunction.java 1415149 2012-11-29 13:12:55Z erans $
    024     * @since 2.0
    025     * @deprecated as of 3.1 replaced by {@link org.apache.commons.math3.analysis.differentiation.MultivariateDifferentiableFunction}
    026     */
    027    @Deprecated
    028    public interface DifferentiableMultivariateFunction extends MultivariateFunction {
    029
    030        /**
    031         * Returns the partial derivative of the function with respect to a point coordinate.
    032         * <p>
    033         * The partial derivative is defined with respect to point coordinate
    034         * x<sub>k</sub>. If the partial derivatives with respect to all coordinates are
    035         * needed, it may be more efficient to use the {@link #gradient()} method which will
    036         * compute them all at once.
    037         * </p>
    038         * @param k index of the coordinate with respect to which the partial
    039         * derivative is computed
    040         * @return the partial derivative function with respect to k<sup>th</sup> point coordinate
    041         */
    042        MultivariateFunction partialDerivative(int k);
    043
    044        /**
    045         * Returns the gradient function.
    046         * <p>If only one partial derivative with respect to a specific coordinate is
    047         * needed, it may be more efficient to use the {@link #partialDerivative(int)} method
    048         * which will compute only the specified component.</p>
    049         * @return the gradient function
    050         */
    051        MultivariateVectorFunction gradient();
    052
    053    }