org.apache.commons.math.ode.nonstiff

## Class ThreeEighthesIntegrator

- java.lang.Object
- - org.apache.commons.math.ode.AbstractIntegrator
  - - org.apache.commons.math.ode.nonstiff.RungeKuttaIntegrator
    - - org.apache.commons.math.ode.nonstiff.ThreeEighthesIntegrator

All Implemented Interfaces:
  FirstOrderIntegrator, ODEIntegrator

    public class ThreeEighthesIntegrator
    extends RungeKuttaIntegrator

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:
  1.2
Version:
  $Revision: 810196 $ $Date: 2009-09-01 21:47:46 +0200 (mar. 01 sept. 2009) $
See Also:
  `EulerIntegrator`, `ClassicalRungeKuttaIntegrator`, `GillIntegrator`, `MidpointIntegrator`

### Field Summary

Fields
`private static double[][]` `STATIC_A` Internal weights Butcher array.
`private static double[]` `STATIC_B` Propagation weights Butcher array.
`private static double[]` `STATIC_C` Time steps Butcher array.

### Fields inherited from class org.apache.commons.math.ode.AbstractIntegrator

`isLastStep, resetOccurred, stepHandlers, stepSize, stepStart`

### Constructor Summary

Constructors
Constructor and Description
`ThreeEighthesIntegrator(double step)` Simple constructor.

### Method Summary

### Methods inherited from class org.apache.commons.math.ode.nonstiff.RungeKuttaIntegrator

`integrate`

### Methods inherited from class org.apache.commons.math.ode.AbstractIntegrator

`acceptStep, addEndTimeChecker, addEventHandler, addStepHandler, clearEventHandlers, clearStepHandlers, computeDerivatives, getCurrentSignedStepsize, getCurrentStepStart, getEvaluations, getEventHandlers, getMaxEvaluations, getName, getStepHandlers, requiresDenseOutput, resetEvaluations, sanityChecks, setEquations, setMaxEvaluations, setStateInitialized`

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Field Detail

#### STATIC_C

    private static final double[] STATIC_C

Time steps Butcher array.

#### STATIC_A

    private static final double[][] STATIC_A

Internal weights Butcher array.

#### STATIC_B

    private static final double[] STATIC_B

Propagation weights Butcher array.

### Constructor Detail

#### ThreeEighthesIntegrator

    public ThreeEighthesIntegrator(double step)

Simple constructor. Build a 3/8 integrator with the given step.

Parameters:
  `step` - integration step