ButcherArrayProvider
, ODEIntegrator
public class LutherIntegrator extends RungeKuttaIntegrator
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 1/20where q = √21
Constructor | Description |
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LutherIntegrator(double step) |
Simple constructor.
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Modifier and Type | Method | Description |
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protected org.hipparchus.ode.nonstiff.LutherStateInterpolator |
createInterpolator(boolean forward,
double[][] yDotK,
ODEStateAndDerivative globalPreviousState,
ODEStateAndDerivative globalCurrentState,
EquationsMapper mapper) |
Create an interpolator.
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double[][] |
getA() |
Get the internal weights from Butcher array (without the first empty row).
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double[] |
getB() |
Get the external weights for the high order method from Butcher array.
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double[] |
getC() |
Get the time steps from Butcher array (without the first zero).
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acceptStep, addEventHandler, addEventHandler, addStepHandler, clearEventHandlers, clearStepHandlers, computeDerivatives, getCurrentSignedStepsize, getCurrentStepStart, getEquations, getEvaluations, getEvaluationsCounter, getEventHandlers, getMaxEvaluations, getName, getStepHandlers, getStepSize, getStepStart, initIntegration, isLastStep, resetOccurred, sanityChecks, setIsLastStep, setMaxEvaluations, setStateInitialized, setStepSize, setStepStart
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
integrate, integrate
integrate, singleStep
public LutherIntegrator(double step)
step
- integration steppublic double[] getC()
public double[][] getA()
public double[] getB()
protected org.hipparchus.ode.nonstiff.LutherStateInterpolator createInterpolator(boolean forward, double[][] yDotK, ODEStateAndDerivative globalPreviousState, ODEStateAndDerivative globalCurrentState, EquationsMapper mapper)
createInterpolator
in class RungeKuttaIntegrator
forward
- integration direction indicatoryDotK
- slopes at the intermediate pointsglobalPreviousState
- start of the global stepglobalCurrentState
- end of the global stepmapper
- equations mapper for the all equationsCopyright © 2016–2018 Hipparchus.org. All rights reserved.