Top Description Constructors Methods
org.apache.commons.math3.ode.nonstiff

public Class LutherFieldIntegrator<T extends RealFieldElement<T>>

extends RungeKuttaFieldIntegrator<T extends RealFieldElement<T>>
Class Inheritance
Type Parameters
<T>
the type of the field elements
Imports
org.apache.commons.math3.Field, .RealFieldElement, org.apache.commons.math3.ode.FieldEquationsMapper, .FieldODEStateAndDerivative, org.apache.commons.math3.util.MathArrays

This class implements the Luther sixth order Runge-Kutta integrator for Ordinary Differential Equations.

This method is described in H. A. Luther 1968 paper An explicit Sixth-Order Runge-Kutta Formula.

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

       0   |               0                     0                     0                     0                     0                     0
       1   |               1                     0                     0                     0                     0                     0
      1/2  |              3/8                   1/8                    0                     0                     0                     0
      2/3  |              8/27                  2/27                  8/27                   0                     0                     0
  (7-q)/14 | (  -21 +   9q)/392    (  -56 +   8q)/392    (  336 -  48q)/392    (  -63 +   3q)/392                  0                     0
  (7+q)/14 | (-1155 - 255q)/1960   ( -280 -  40q)/1960   (    0 - 320q)/1960   (   63 + 363q)/1960   ( 2352 + 392q)/1960                 0
       1   | (  330 + 105q)/180    (  120 +   0q)/180    ( -200 + 280q)/180    (  126 - 189q)/180    ( -686 - 126q)/180     ( 490 -  70q)/180
           |--------------------------------------------------------------------------------------------------------------------------------------------------
           |              1/20                   0                   16/45                  0                   49/180                 49/180         1/20
where q = √21

Since
3.6
See Also
EulerFieldIntegrator, ClassicalRungeKuttaFieldIntegrator, GillFieldIntegrator, MidpointFieldIntegrator, ThreeEighthesFieldIntegrator

Constructor Summary

AccessConstructor and Description
public
LutherFieldIntegrator(final Field<T>
field to which the time and state vector elements belong
field
,
final T
integration step
step
)

Simple constructor.

Method Summary

Modifier and TypeMethod and Description
protected LutherFieldStepInterpolator<T>
createInterpolator(final boolean
integration direction indicator
forward
,
T[][]
slopes at the intermediate points
yDotK
,
final FieldODEStateAndDerivative<T>
start of the global step
globalPreviousState
,
final FieldODEStateAndDerivative<T>
end of the global step
globalCurrentState
,
final FieldEquationsMapper<T>
equations mapper for the all equations
mapper
)

Implements abstract org.apache.commons.math3.ode.nonstiff.RungeKuttaFieldIntegrator.createInterpolator.

Create an interpolator.

public T[][]
getA()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getA.

Get the internal weights from Butcher array (without the first empty row).

public T[]
getB()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getB.

Get the external weights for the high order method from Butcher array.

public T[]
getC()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getC.

Get the time steps from Butcher array (without the first zero).

Inherited from org.apache.commons.math3.ode.nonstiff.RungeKuttaFieldIntegrator:
fractionintegratesingleStep

Constructor Detail

LutherFieldIntegratorback to summary
public LutherFieldIntegrator(final Field<T> field, final T step)

Simple constructor. Build a fourth-order Luther integrator with the given step.

Parameters
field:Field<T>

field to which the time and state vector elements belong

step:T

integration step

Method Detail

createInterpolatorback to summary
protected LutherFieldStepInterpolator<T> createInterpolator(final boolean forward, T[][] yDotK, final FieldODEStateAndDerivative<T> globalPreviousState, final FieldODEStateAndDerivative<T> globalCurrentState, final FieldEquationsMapper<T> mapper)

Implements abstract org.apache.commons.math3.ode.nonstiff.RungeKuttaFieldIntegrator.createInterpolator.

Doc from org.apache.commons.math3.ode.nonstiff.RungeKuttaFieldIntegrator.createInterpolator.

Create an interpolator.

Parameters
forward:boolean

integration direction indicator

yDotK:T[][]

slopes at the intermediate points

globalPreviousState:FieldODEStateAndDerivative<T>

start of the global step

globalCurrentState:FieldODEStateAndDerivative<T>

end of the global step

mapper:FieldEquationsMapper<T>

equations mapper for the all equations

Returns:LutherFieldStepInterpolator<T>

external weights for the high order method from Butcher array

Annotations
@Override
getAback to summary
public T[][] getA()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getA.

Doc from org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getA.

Get the internal weights from Butcher array (without the first empty row).

Returns:T[][]

internal weights from Butcher array (without the first empty row)

getBback to summary
public T[] getB()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getB.

Doc from org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getB.

Get the external weights for the high order method from Butcher array.

Returns:T[]

external weights for the high order method from Butcher array

getCback to summary
public T[] getC()

Implements org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getC.

Doc from org.apache.commons.math3.ode.nonstiff.FieldButcherArrayProvider.getC.

Get the time steps from Butcher array (without the first zero).

Returns:T[]

time steps from Butcher array (without the first zero