| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.commons.math.analysis; |
| |
| /** |
| * Extension of {@link MultivariateRealFunction} representing a differentiable |
| * multivariate real function. |
| * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $ |
| * @since 2.0 |
| */ |
| public interface DifferentiableMultivariateRealFunction extends MultivariateRealFunction { |
| |
| /** |
| * Returns the partial derivative of the function with respect to a point coordinate. |
| * <p> |
| * The partial derivative is defined with respect to point coordinate |
| * x<sub>k</sub>. If the partial derivatives with respect to all coordinates are |
| * needed, it may be more efficient to use the {@link #gradient()} method which will |
| * compute them all at once. |
| * </p> |
| * @param k index of the coordinate with respect to which the partial |
| * derivative is computed |
| * @return the partial derivative function with respect to k<sup>th</sup> point coordinate |
| */ |
| MultivariateRealFunction partialDerivative(int k); |
| |
| /** |
| * Returns the gradient function. |
| * <p>If only one partial derivative with respect to a specific coordinate is |
| * needed, it may be more efficient to use the {@link #partialDerivative(int)} method |
| * which will compute only the specified component.</p> |
| * @return the gradient function |
| */ |
| MultivariateVectorialFunction gradient(); |
| |
| } |