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    }