[sundials-users] [LLNL/sundials] Release v7.3.0 - SUNDIALS v7.3.0

[David Gardner]

SUNDIALS v7.3.0

Repository: LLNL/sundials · Tag: v7.3.0 · Commit: e941546 · Released by: gardner48

Major Features

A new discrete adjoint capability for explicit Runge-Kutta methods has been added to the ARKODE ERKStep and ARKStep stepper modules. This is based on a new set of shared classes, SUNAdjointStepper and SUNAdjointCheckpointScheme. A new example demonstrating this capability can be found in examples/arkode/C_serial/ark_lotka_volterra_ASA.c.

New Features and Enhancements

ARKODE

The following changes have been made to the default ERK, DIRK, and ARK methods in ARKODE to utilize more efficient methods:

Type	Old Default	New Default
2nd Order Explicit	ARKODE_HEUN_EULER_2_1_2	ARKODE_RALSTON_3_1_2
4th Order Explicit	ARKODE_ZONNEVELD_5_3_4	ARKODE_SOFRONIOU_SPALETTA_5_3_4
5th Order Explicit	ARKODE_CASH_KARP_6_4_5	ARKODE_TSITOURAS_7_4_5
6th Order Explicit	ARKODE_VERNER_8_5_6	ARKODE_VERNER_9_5_6
8th Order Explicit	ARKODE_FEHLBERG_13_7_8	ARKODE_VERNER_13_7_8
2nd Order Implicit	ARKODE_SDIRK_2_1_2	ARKODE_ARK2_DIRK_3_1_2
3rd Order Implicit	ARKODE_ARK324L2SA_DIRK_4_2_3	ARKODE_ESDIRK325L2SA_5_2_3
4th Order Implicit	ARKODE_SDIRK_5_3_4	ARKODE_ESDIRK436L2SA_6_3_4
5th Order Implicit	ARKODE_ARK548L2SA_DIRK_8_4_5	ARKODE_ESDIRK547L2SA2_7_4_5
4th Order ARK	ARKODE_ARK436L2SA_ERK_6_3_4 and ARKODE_ARK436L2SA_DIRK_6_3_4	ARKODE_ARK437L2SA_ERK_7_3_4 and ARKODE_ARK437L2SA_DIRK_7_3_4
5th Order ARK	ARKODE_ARK548L2SA_ERK_8_4_5 and ARKODE_ARK548L2SA_DIRK_8_4_5	ARKODE_ARK548L2SAb_ERK_8_4_5 and ARKODE_ARK548L2SAb_DIRK_8_4_5

The old default methods can be loaded using the functions ERKStepSetTableName or ERKStepSetTableNum with ERKStep and ARKStepSetTableName or ARKStepSetTableNum with ARKStep and passing the desired method name string or constant, respectively. For example, the following call can be used to load the old default fourth order method with ERKStep:

/* Load the old 4th order ERK method using the table name */
ierr = ERKStepSetTableName(arkode_mem, "ARKODE_ZONNEVELD_5_3_4");

Similarly with ARKStep, the following calls can be used for ERK, DIRK, or ARK
methods, respectively:

/* Load the old 4th order ERK method by name */
ierr = ARKStepSetTableName(arkode_mem, "ARKODE_DIRK_NONE", "ARKODE_ZONNEVELD_5_3_4");

/* Load the old 4th order DIRK method by name */
ierr = ARKStepSetTableName(arkode_mem, "ARKODE_SDIRK_5_3_4", "ARKODE_ERK_NONE");

/* Load the old 4th order ARK method by name */
ierr = ARKStepSetTableName(arkode_mem, "ARKODE_ARK436L2SA_DIRK_6_3_4", "ARKODE_ARK436L2SA_ERK_6_3_4");

Additionally, the following changes have been made to the default time step adaptivity parameters in ARKODE:

Parameter	Old Default	New Default
Controller	PID (PI for ERKStep)	I
Safety Factor	0.96	0.9
Bias	1.5 (1.2 for ERKStep)	1.0
Fixed Step Bounds	[1.0, 1.5]	[1.0, 1.0]
Adaptivity Adjustment	-1	0

The following calls can be used to restore the old defaults for ERKStep:

SUNAdaptController controller = SUNAdaptController_Soderlind(ctx);
SUNAdaptController_SetParams_PI(controller, 0.8, -0.31);
ARKodeSetAdaptController(arkode_mem, controller);
SUNAdaptController_SetErrorBias(controller, 1.2);
ARKodeSetSafetyFactor(arkode_mem, 0.96);
ARKodeSetFixedStepBounds(arkode_mem, 1, 1.5);
ARKodeSetAdaptivityAdjustment(arkode_mem, -1);

The following calls can be used to restore the old defaults for other ARKODE integrators:

SUNAdaptController controller = SUNAdaptController_PID(ctx);
ARKodeSetAdaptController(arkode_mem, controller);
SUNAdaptController_SetErrorBias(controller, 1.5);
ARKodeSetSafetyFactor(arkode_mem, 0.96);
ARKodeSetFixedStepBounds(arkode_mem, 1, 1.5);
ARKodeSetAdaptivityAdjustment(arkode_mem, -1);

In both cases above, destroy the controller at the end of the run with SUNAdaptController_Destroy(controller);.

The Soderlind time step adaptivity controller now starts with an I controller until there is sufficient history of past time steps and errors.

Added ARKodeSetAdaptControllerByName to set a time step adaptivity controller with a string. There are also four new controllers: SUNAdaptController_H0211, SUNAdaptController_H0321, SUNAdaptController_H211, and SUNAdaptController_H312.

Added the ARKODE_RALSTON_3_1_2 and ARKODE_TSITOURAS_7_4_5 explicit Runge-Kutta Butcher tables.

Improved the precision of the coefficients for ARKODE_ARK324L2SA_ERK_4_2_3, ARKODE_VERNER_9_5_6, ARKODE_VERNER_10_6_7, ARKODE_VERNER_13_7_8, ARKODE_ARK324L2SA_DIRK_4_2_3, and ARKODE_ESDIRK324L2SA_4_2_3.

CVODE / CVODES

Added support for resizing CVODE and CVODES when solving initial value problems where the number of equations and unknowns changes over time. Resizing requires a user supplied history of solution and right-hand side values at the new problem size, see CVodeResizeHistory for more information.

KINSOL

Added support in KINSOL for setting user-supplied functions to compute the damping factor and, when using Anderson acceleration, the depth in fixed-point or Picard iterations. See KINSetDampingFn and KINSetDepthFn, respectively, for more information.

SUNDIALS Types

A new type, suncountertype, was added for the integer type used for counter variables. It is currently an alias for long int.

Bug Fixes

ARKODE

Fixed bug in ARKodeResize which caused it return an error for MRI methods.

Removed error floors from the SUNAdaptController implementations which could unnecessarily limit the time size growth, particularly after the first step.

Fixed bug in ARKodeSetFixedStep where it could return ARK_SUCCESS despite an error occurring.

Fixed bug in the ARKODE SPRKStep SPRKStepReInit function and ARKodeReset function with SPRKStep that could cause a segmentation fault when compensated summation is not used.

KINSOL

Fixed a bug in KINSOL where an incorrect damping parameter is applied on the initial iteration with Anderson acceleration unless KINSetDamping and KINSetDampingAA are both called with the same value when enabling damping.

Fixed a bug in KINSOL where errors that occurred when computing Anderson acceleration were not captured.

Added missing return values to KINGetReturnFlagName.

CMake

Fixed the behavior of SUNDIALS_ENABLE_ERROR_CHECKS so additional runtime error checks are disabled by default with all release build types. Previously, MinSizeRel builds enabled additional error checking by default.

Deprecation Notices

All work space functions, e.g., CVodeGetWorkSpace and ARKodeGetLinWorkSpace, have been deprecated and will be removed in version 8.0.0.

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This release has 15 assets:

• arkode-6.3.0.tar.gz
• ark_examples.pdf
• cvode-7.3.0.tar.gz
• cvodes-7.3.0.tar.gz
• cvs_examples.pdf
• cv_examples.pdf
• ida-7.3.0.tar.gz
• idas-6.3.0.tar.gz
• idas_examples.pdf
• ida_examples.pdf
• kinsol-7.3.0.tar.gz
• kin_examples.pdf
• sundials-7.3.0.tar.gz
• Source code (zip)
• Source code (tar.gz)

Visit the release page to download them.

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