public interface SecondaryODE
In some cases users may need to integrate some problem-specific equations along with a primary set of differential equations. One example is optimal control where adjoined parameters linked to the minimized hamiltonian must be integrated.
|Modifier and Type||Method and Description|
Compute the derivatives related to the secondary state parameters.
Get the dimension of the secondary state parameters.
Initialize equations at the start of an ODE integration.
default void init(double t0, double primary0, double secondary0, 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 start
primary0- array containing the value of the primary state vector at integration start
secondary0- array containing the value of the secondary state vector at integration start
finalTime- target time for the integration
double computeDerivatives(double t, double primary, double primaryDot, double secondary) throws MathIllegalArgumentException, MathIllegalStateException
In some cases, additional equations can require to change the derivatives
of the primary state (i.e. the content of the
One use case is optimal control, when the secondary equations handle co-state,
which changes control, and the control changes the primary state. In this
case, the primary and secondary equations are not really independent from each
other, so if possible it would be better to put state and co-state and their
equations all in the primary equations. As this is not always possible, this
array. This array will be used to evolve the primary state only
t- current value of the independent time variable
primary- array containing the current value of the primary state vector
primaryDot- array containing the derivative of the primary state vector (the method is allowed to change the derivatives here, when the additional equations do have an effect on the primary equations)
secondary- array containing the current value of the secondary state vector
MathIllegalStateException- if the number of functions evaluations is exceeded
MathIllegalArgumentException- if arrays dimensions do not match equations settings
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