| /* |
| * 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.ode.jacobians; |
| |
| import org.apache.commons.math.ode.DerivativeException; |
| |
| /** |
| * This interface represents a handler that should be called after |
| * each successful step. |
| * |
| * <p>The ODE integrators compute the evolution of the state vector at |
| * some grid points that depend on their own internal algorithm. Once |
| * they have found a new grid point (possibly after having computed |
| * several evaluation of the derivative at intermediate points), they |
| * provide it to objects implementing this interface. These objects |
| * typically either ignore the intermediate steps and wait for the |
| * last one, store the points in an ephemeris, or forward them to |
| * specialized processing or output methods.</p> |
| * |
| * <p>Note that is is possible to register a {@link |
| * org.apache.commons.math.ode.sampling.StepHandler classical step handler} |
| * in the low level integrator used to build a {@link FirstOrderIntegratorWithJacobians} |
| * rather than implementing this class. The step handlers registered at low level |
| * will see the big compound state whether the step handlers defined by this interface |
| * see the original state, and its jacobians in separate arrays.</p> |
| * |
| * <p>The compound state is guaranteed to contain the original state in the first |
| * elements, followed by the jacobian with respect to initial state (in row order), |
| * followed by the jacobian with respect to parameters (in row order). If for example |
| * the original state dimension is 6 and there are 3 parameters, the compound state will |
| * be a 60 elements array. The first 6 elements will be the original state, the next 36 |
| * elements will be the jacobian with respect to initial state, and the remaining 18 elements |
| * will be the jacobian with respect to parameters.</p> |
| * |
| * <p>Dealing with low level step handlers is cumbersome if one really needs the jacobians |
| * in these methods, but it also prevents many data being copied back and forth between |
| * state and jacobians on one side and compound state on the other side. So for performance |
| * reasons, it is recommended to use this interface <em>only</em> if jacobians are really |
| * needed and to use lower level handlers if only state is needed.</p> |
| * |
| * @see FirstOrderIntegratorWithJacobians |
| * @see StepInterpolatorWithJacobians |
| * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 févr. 2011) $ |
| * @since 2.1 |
| * @deprecated as of 2.2 the complete package is deprecated, it will be replaced |
| * in 3.0 by a completely rewritten implementation |
| */ |
| @Deprecated |
| public interface StepHandlerWithJacobians { |
| |
| /** Determines whether this handler needs dense output. |
| * <p>This method allows the integrator to avoid performing extra |
| * computation if the handler does not need dense output.</p> |
| * @return true if the handler needs dense output |
| */ |
| boolean requiresDenseOutput(); |
| |
| /** Reset the step handler. |
| * Initialize the internal data as required before the first step is |
| * handled. |
| */ |
| void reset(); |
| |
| /** |
| * Handle the last accepted step |
| * @param interpolator interpolator for the last accepted step. For |
| * efficiency purposes, the various integrators reuse the same |
| * object on each call, so if the instance wants to keep it across |
| * all calls (for example to provide at the end of the integration a |
| * continuous model valid throughout the integration range, as the |
| * {@link org.apache.commons.math.ode.ContinuousOutputModel |
| * ContinuousOutputModel} class does), it should build a local copy |
| * using the clone method of the interpolator and store this copy. |
| * Keeping only a reference to the interpolator and reusing it will |
| * result in unpredictable behavior (potentially crashing the application). |
| * @param isLast true if the step is the last one |
| * @throws DerivativeException this exception is propagated to the |
| * caller if the underlying user function triggers one |
| */ |
| void handleStep(StepInterpolatorWithJacobians interpolator, boolean isLast) throws DerivativeException; |
| |
| } |