This integrator is an embedded Runge-Kutta integrator of order 8(5,3) used in local extrapolation mode (i.e. the solution is computed using the high order formula) with stepsize control (and automatic step initialization) and continuous output. This method uses 12 functions evaluations per step for integration and 4 evaluations for interpolation. However, since the first interpolation evaluation is the same as the first integration evaluation of the next step, we have included it in the integrator rather than in the interpolator and specified the method was an fsal. Hence, despite we have 13 stages here, the cost is really 12 evaluations per step even if no interpolation is done, and the overcost of interpolation is only 3 evaluations.
This method is based on an 8(6) method by Dormand and Prince (i.e. order 8 for the integration and order 6 for error estimation) modified by Hairer and Wanner to use a 5th order error estimator with 3rd order correction. This modification was introduced because the original method failed in some cases (wrong steps can be accepted when step size is too large, for example in the Brusselator problem) and also had severe difficulties when applied to problems with discontinuities. This modification is explained in the second edition of the first volume (Nonstiff Problems) of the reference book by Hairer, Norsett and Wanner: Solving Ordinary Differential Equations (Springer-Verlag, ISBN 3-540-56670-8).
| Modifier and Type | Field and Description |
|---|---|
| private static final double | E1_01
First error weights array, element 1. |
| private static final double | E1_06
First error weights array, element 6. |
| private static final double | E1_07
First error weights array, element 7. |
| private static final double | E1_08
First error weights array, element 8. |
| private static final double | E1_09
First error weights array, element 9. |
| private static final double | E1_10
First error weights array, element 10. |
| private static final double | E1_11
First error weights array, element 11. |
| private static final double | E1_12
First error weights array, element 12. |
| private static final double | E2_01
Second error weights array, element 1. |
| private static final double | E2_06
Second error weights array, element 6. |
| private static final double | E2_07
Second error weights array, element 7. |
| private static final double | E2_08
Second error weights array, element 8. |
| private static final double | E2_09
Second error weights array, element 9. |
| private static final double | E2_10
Second error weights array, element 10. |
| private static final double | E2_11
Second error weights array, element 11. |
| private static final double | E2_12
Second error weights array, element 12. |
| private static final String | METHOD_NAME
Integrator method name. |
| private static final double[][] | STATIC_A
Internal weights Butcher array. |
| private static final double[] | STATIC_B
Propagation weights Butcher array. |
| private static final double[] | STATIC_C
Time steps Butcher array. |
| Access | Constructor and Description |
|---|---|
| public | DormandPrince853Integrator(final double
minimal step (sign is irrelevant, regardless of
integration direction, forward or backward), the last step can
be smaller than this minStep, final double maximal step (sign is irrelevant, regardless of
integration direction, forward or backward), the last step can
be smaller than this maxStep, final double allowed absolute error scalAbsoluteTolerance, final double allowed relative error scalRelativeTolerance)Simple constructor. |
| public | DormandPrince853Integrator(final double
minimal step (sign is irrelevant, regardless of
integration direction, forward or backward), the last step can
be smaller than this minStep, final double maximal step (sign is irrelevant, regardless of
integration direction, forward or backward), the last step can
be smaller than this maxStep, final double[] allowed absolute error vecAbsoluteTolerance, final double[] allowed relative error vecRelativeTolerance)Simple constructor. |
| Modifier and Type | Method and Description |
|---|---|
| protected double | estimateError(final double[][]
derivatives computed during the first stages yDotK, final double[] estimate of the step at the start of the step y0, final double[] estimate of the step at the end of the step y1, final double current step h)Implements abstract org. Compute the error ratio. |
| public int | getOrder()
Implements abstract org. Get the order of the method. |
| E1_01 | back to summary |
|---|---|
| private static final double E1_01 First error weights array, element 1. | |
| E1_06 | back to summary |
|---|---|
| private static final double E1_06 First error weights array, element 6. | |
| E1_07 | back to summary |
|---|---|
| private static final double E1_07 First error weights array, element 7. | |
| E1_08 | back to summary |
|---|---|
| private static final double E1_08 First error weights array, element 8. | |
| E1_09 | back to summary |
|---|---|
| private static final double E1_09 First error weights array, element 9. | |
| E1_10 | back to summary |
|---|---|
| private static final double E1_10 First error weights array, element 10. | |
| E1_11 | back to summary |
|---|---|
| private static final double E1_11 First error weights array, element 11. | |
| E1_12 | back to summary |
|---|---|
| private static final double E1_12 First error weights array, element 12. | |
| E2_01 | back to summary |
|---|---|
| private static final double E2_01 Second error weights array, element 1. | |
| E2_06 | back to summary |
|---|---|
| private static final double E2_06 Second error weights array, element 6. | |
| E2_07 | back to summary |
|---|---|
| private static final double E2_07 Second error weights array, element 7. | |
| E2_08 | back to summary |
|---|---|
| private static final double E2_08 Second error weights array, element 8. | |
| E2_09 | back to summary |
|---|---|
| private static final double E2_09 Second error weights array, element 9. | |
| E2_10 | back to summary |
|---|---|
| private static final double E2_10 Second error weights array, element 10. | |
| E2_11 | back to summary |
|---|---|
| private static final double E2_11 Second error weights array, element 11. | |
| E2_12 | back to summary |
|---|---|
| private static final double E2_12 Second error weights array, element 12. | |
| METHOD_NAME | back to summary |
|---|---|
| private static final String METHOD_NAME Integrator method name. | |
| STATIC_A | back to summary |
|---|---|
| private static final double[][] STATIC_A Internal weights Butcher array. | |
| STATIC_B | back to summary |
|---|---|
| private static final double[] STATIC_B Propagation weights Butcher array. | |
| STATIC_C | back to summary |
|---|---|
| private static final double[] STATIC_C Time steps Butcher array. | |
| DormandPrince853Integrator | back to summary |
|---|---|
| public DormandPrince853Integrator(final double minStep, final double maxStep, final double scalAbsoluteTolerance, final double scalRelativeTolerance) Simple constructor. Build an eighth order Dormand-Prince integrator with the given step bounds
| |
| DormandPrince853Integrator | back to summary |
|---|---|
| public DormandPrince853Integrator(final double minStep, final double maxStep, final double[] vecAbsoluteTolerance, final double[] vecRelativeTolerance) Simple constructor. Build an eighth order Dormand-Prince integrator with the given step bounds
| |
| estimateError | back to summary |
|---|---|
| protected double estimateError(final double[][] yDotK, final double[] y0, final double[] y1, final double h) Implements abstract org. Doc from org. Compute the error ratio.
| |
| getOrder | back to summary |
|---|---|
| public int getOrder() Implements abstract org. Doc from org. Get the order of the method.
| |