public interface OrdinaryDifferentialEquation
This interface should be implemented by all real first order
differential equation problems before they can be handled by the
integrators ODEIntegrator.integrate(OrdinaryDifferentialEquation,
ODEState, double)
method.
A first order differential equations problem, as seen by an
integrator is the time derivative dY/dt
of a state
vector Y
, both being one dimensional arrays. From the
integrator point of view, this derivative depends only on the
current time t
and on the state vector
Y
.
For real problems, the derivative depends also on parameters that do not belong to the state vector (dynamical model constants for example). These constants are completely outside of the scope of this interface, the classes that implement it are allowed to handle them as they want.
ODEIntegrator
,
FirstOrderConverter
,
SecondOrderODE
Modifier and Type  Method and Description 

double[] 
computeDerivatives(double t,
double[] y)
Get the current time derivative of the state vector.

int 
getDimension()
Get the dimension of the problem.

default void 
init(double t0,
double[] y0,
double finalTime)
Initialize equations at the start of an ODE integration.

int getDimension()
default void init(double t0, double[] y0, double finalTime)
This method is called once at the start of the integration. It may be used by the equations to initialize some internal data if needed.
The default implementation does nothing.
t0
 value of the independent time variable at integration starty0
 array containing the value of the state vector at integration startfinalTime
 target time for the integrationdouble[] computeDerivatives(double t, double[] y)
t
 current value of the independent time variabley
 array containing the current value of the state vectorCopyright © 2016–2020 Hipparchus.org. All rights reserved.