Package org.apache.commons.math3.ode.nonstiff

Class ThreeEighthesFieldIntegrator<T extends RealFieldElement<T>>

java.lang.Object
org.apache.commons.math3.ode.AbstractFieldIntegrator<T>
org.apache.commons.math3.ode.nonstiff.RungeKuttaFieldIntegrator<T>
org.apache.commons.math3.ode.nonstiff.ThreeEighthesFieldIntegrator<T>
Type Parameters:
T - the type of the field elements
All Implemented Interfaces:
FirstOrderFieldIntegrator<T>, FieldButcherArrayProvider<T>
public class ThreeEighthesFieldIntegrator<T extends RealFieldElement<T>> extends RungeKuttaFieldIntegrator<T>
This class implements the 3/8 fourth order Runge-Kutta integrator for Ordinary Differential Equations.

This method is an explicit Runge-Kutta method, its Butcher-array is the following one : 

    0  |  0    0    0    0
   1/3 | 1/3   0    0    0
   2/3 |-1/3   1    0    0
    1  |  1   -1    1    0
       |--------------------
       | 1/8  3/8  3/8  1/8

Since:
3.6
See Also:

  • Constructor Details

    • ThreeEighthesFieldIntegrator

      public ThreeEighthesFieldIntegrator(Field<T> field, T step)
      Simple constructor. Build a 3/8 integrator with the given step.
      Parameters:
      field - field to which the time and state vector elements belong
      step - integration step

  • Method Details

    • getC

      public T[] getC()
      Get the time steps from Butcher array (without the first zero).
      Returns:
      time steps from Butcher array (without the first zero

    • getA

      public T[][] getA()
      Get the internal weights from Butcher array (without the first empty row).
      Returns:
      internal weights from Butcher array (without the first empty row)

    • getB

      public T[] getB()
      Get the external weights for the high order method from Butcher array.
      Returns:
      external weights for the high order method from Butcher array

    • createInterpolator

      protected org.apache.commons.math3.ode.nonstiff.ThreeEighthesFieldStepInterpolator<T> createInterpolator(boolean forward, T[][] yDotK, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldEquationsMapper<T> mapper)
      Create an interpolator.
      Specified by:
      createInterpolator in class RungeKuttaFieldIntegrator<T extends RealFieldElement<T>>
      Parameters:
      forward - integration direction indicator
      yDotK - slopes at the intermediate points
      globalPreviousState - start of the global step
      globalCurrentState - end of the global step
      mapper - equations mapper for the all equations
      Returns:
      external weights for the high order method from Butcher array