| // 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.spaceroots.mantissa.utilities; |
| |
| /** This interface is used to map objects to and from simple arrays. |
| * |
| * <p> Lots of mathematical algorithms are generic ones which can |
| * process the data from domain objects despite they ignore what |
| * this data represent. As an example, the same algorithm can |
| * integrate either the orbit evolution of a spacecraft under a |
| * specified force model or the electrical characteristics of a |
| * circuit after a switch is opened. </p> |
| |
| * <p> The approach of the Mantissa library is to define an interface |
| * for each such algorithm to represent the type of problem they can |
| * handle ({@link |
| * org.spaceroots.mantissa.ode.FirstOrderDifferentialEquations |
| * FirstOrderDifferentialEquations} for an ODE integrators, {@link |
| * org.spaceroots.mantissa.estimation.EstimationProblem |
| * EstimationProblem} for least squares estimators, ...). Furthermore, |
| * the state data that is handled by these algorithms is often a |
| * mixture of data coming from several domain objects (the orbit, |
| * plus the aerodynamical coefficients of the spacecraft, plus the |
| * characteristics of the thrusters, plus ...). Therefore, the user |
| * needs to gather and dispatch data between different objects |
| * representing different levels of abstraction. </p> |
| |
| * <p> This interface is designed to copy data back and forth between |
| * existing objects during the iterative processing of these |
| * algorithms and avoid the cost of recreating the objects. </p> |
| |
| * <p> The nominal way to use this interface is to have the domain |
| * objects implement it (either directly or using inheritance to add |
| * this feature to already existing objects) and to create one class |
| * that implements the problem interface (for example {@link |
| * org.spaceroots.mantissa.ode.FirstOrderDifferentialEquations}) and |
| * uses the {@link ArrayMapper} class to dispatch the data to and from |
| * the domain objects.</p> |
| |
| * @see ArrayMapper |
| * |
| * @version $Id$ |
| * @author L. Maisonobe |
| * |
| */ |
| |
| public interface ArraySliceMappable { |
| |
| /** Get the dimension of the object. |
| * @return dimension of the object |
| */ |
| public int getStateDimension(); |
| |
| /** Reinitialize internal state from the specified array slice data. |
| * @param start start index in the array |
| * @param array array holding the data to extract |
| */ |
| public void mapStateFromArray(int start, double[] array); |
| |
| /** Store internal state data into the specified array slice. |
| * @param start start index in the array |
| * @param array array where data should be stored |
| */ |
| public void mapStateToArray(int start, double[] array); |
| |
| } |