org.apache.commons.math.ode.ExtendedFirstOrderDifferentialEquations Maven / Gradle / Ivy
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* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.commons.math.ode;
/** This interface represents a first order differential equations set
* with a main set of equations and an extension set.
*
*
* This interface is a simple extension on the {@link
* FirstOrderDifferentialEquations} that allows to identify which part
* of a complete set of differential equations correspond to the main
* set and which part correspond to the extension set.
*
*
* One typical use case is the computation of Jacobians. The main
* set of equations correspond to the raw ode, and we add to this set
* another bunch of equations which represent the jacobians of the
* main set. In that case, we want the integrator to use only
* the main set to estimate the errors and hence the step sizes. It should
* not use the additional equations in this computation. If the
* complete ode implements this interface, the {@link FirstOrderIntegrator
* integrator} will be able to know where the main set ends and where the
* extended set begins.
*
*
* We consider that the main set always corresponds to the first equations
* and the extended set to the last equations.
*
*
* @see FirstOrderDifferentialEquations
*
* @version $Revision: 980981 $ $Date: 2010-07-31 00:03:04 +0200 (sam. 31 juil. 2010) $
* @since 2.2
*/
public interface ExtendedFirstOrderDifferentialEquations extends FirstOrderDifferentialEquations {
/** Return the dimension of the main set of equations.
*
* The main set of equations represent the first part of an ODE state.
* The error estimations and adaptive step size computation should be
* done on this first part only, not on the final part of the state
* which represent an extension set of equations which are considered
* secondary.
*
* @return dimension of the main set of equations, must be lesser than or
* equal to the {@link #getDimension() total dimension}
*/
int getMainSetDimension();
}