Interface SecondOrderDifferentialEquations

public interface SecondOrderDifferentialEquations
This interface represents a second order differential equations set.This interface should be implemented by all real second order differential equation problems before they can be handled by the integrators
SecondOrderIntegrator.integrate(org.apache.commons.math.ode.SecondOrderDifferentialEquations, double, double[], double[], double, double[], double[])
method.A second order differential equations problem, as seen by an integrator is the second time derivative
d2Y/dt^2
of a state vectorY
, both being one dimensional arrays. From the integrator point of view, this derivative depends only on the current timet
, on the state vectorY
and on the first time derivative of the state vector.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.
 Since:
 1.2
 See Also:
SecondOrderIntegrator
,FirstOrderConverter
,FirstOrderDifferentialEquations


Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
computeSecondDerivatives(double t, double[] y, double[] yDot, double[] yDDot)
Get the current time derivative of the state vector.int
getDimension()
Get the dimension of the problem.



Method Detail

getDimension
int getDimension()
Get the dimension of the problem. Returns:
 dimension of the problem

computeSecondDerivatives
void computeSecondDerivatives(double t, double[] y, double[] yDot, double[] yDDot) throws DerivativeException
Get the current time derivative of the state vector. Parameters:
t
 current value of the independent time variabley
 array containing the current value of the state vectoryDot
 array containing the current value of the first derivative of the state vectoryDDot
 placeholder array where to put the second time derivative of the state vector Throws:
DerivativeException
 this userdefined exception should be used if an error is is triggered by user code

