Package org.hipparchus.ode.nonstiff
Class LutherFieldIntegrator<T extends CalculusFieldElement<T>>
- java.lang.Object
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- org.hipparchus.ode.AbstractFieldIntegrator<T>
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- org.hipparchus.ode.nonstiff.FixedStepRungeKuttaFieldIntegrator<T>
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- org.hipparchus.ode.nonstiff.LutherFieldIntegrator<T>
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- Type Parameters:
T
- the type of the field elements
- All Implemented Interfaces:
FieldODEIntegrator<T>
,FieldButcherArrayProvider<T>
,FieldExplicitRungeKuttaIntegrator<T>
public class LutherFieldIntegrator<T extends CalculusFieldElement<T>> extends FixedStepRungeKuttaFieldIntegrator<T>
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
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Field Summary
Fields Modifier and Type Field Description static String
METHOD_NAME
Name of integration scheme.
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Constructor Summary
Constructors Constructor Description LutherFieldIntegrator(Field<T> field, T step)
Simple constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected LutherFieldStateInterpolator<T>
createInterpolator(boolean forward, T[][] yDotK, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldEquationsMapper<T> mapper)
Create an interpolator.T[][]
getA()
Get the internal weights from Butcher array (without the first empty row).T[]
getB()
Get the external weights for the high order method from Butcher array.T[]
getC()
Get the time steps from Butcher array (without the first zero).-
Methods inherited from class org.hipparchus.ode.nonstiff.FixedStepRungeKuttaFieldIntegrator
getDefaultStep, getNumberOfStages, initIntegration, integrate, isUsingFieldCoefficients, setUsingFieldCoefficients
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Methods inherited from class org.hipparchus.ode.AbstractFieldIntegrator
acceptStep, addEventDetector, addStepEndHandler, addStepHandler, clearEventDetectors, clearStepEndHandlers, clearStepHandlers, computeDerivatives, getCurrentSignedStepsize, getEquations, getEvaluations, getEvaluationsCounter, getEventDetectors, getField, getMaxEvaluations, getName, getStepEndHandlers, getStepHandlers, getStepSize, getStepStart, incrementEvaluations, isLastStep, resetOccurred, sanityChecks, setIsLastStep, setMaxEvaluations, setStateInitialized, setStepSize, setStepStart
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.hipparchus.ode.nonstiff.FieldExplicitRungeKuttaIntegrator
getRealA, getRealB, getRealC, singleStep
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Methods inherited from interface org.hipparchus.ode.FieldODEIntegrator
addEventDetector, addStepEndHandler, addStepHandler, clearEventDetectors, clearStepEndHandlers, clearStepHandlers, getCurrentSignedStepsize, getEvaluations, getEventDetectors, getMaxEvaluations, getName, getStepEndHandlers, getStepHandlers, getStepStart, setMaxEvaluations
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Field Detail
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METHOD_NAME
public static final String METHOD_NAME
Name of integration scheme.- See Also:
- Constant Field Values
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Method Detail
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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
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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)
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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
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createInterpolator
protected LutherFieldStateInterpolator<T> createInterpolator(boolean forward, T[][] yDotK, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldEquationsMapper<T> mapper)
Create an interpolator.- Specified by:
createInterpolator
in classFixedStepRungeKuttaFieldIntegrator<T extends CalculusFieldElement<T>>
- Parameters:
forward
- integration direction indicatoryDotK
- slopes at the intermediate pointsglobalPreviousState
- start of the global stepglobalCurrentState
- end of the global stepmapper
- equations mapper for the all equations- Returns:
- external weights for the high order method from Butcher array
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