KmlDssSolve

To perform back substitution on a matrix, you need to call KmlDssFactorize to factorize the matrix first.

Interface Definition

C interface:

int KmlDssSolve(KmlDssSolver *solver, const KmlSolverMatrix *b, KmlSolverMatrix *x, const KmlDssSolveOption *option);

Parameters

Parameter	Type	Description	Input/Output
solver	KmlDssSolver *	Solver handle created by KmlDssInit.	Input
b	KmlSolverMatrix *	Pointer to the RHS vector structure, which is essentially a matrix and is created by the KmlSolverMatrixCreate function. The pointer cannot be null.	Input
x	KmlSolverMatrix *	Pointer to the solution space structure, which is essentially a matrix and is created by the KmlSolverMatrixCreate function. The input cannot be a null pointer, and the output is a numerical array containing the solved x.	Output
option	KmlDssSolveOption *	Configuration in the factorization phase, which cannot be a null pointer. For details, see Table 1.	Input

**Table 1** KmlDssSolveOption structure
Field	Type	Description
fieldMask	uint64_t	Mask that determines to which fields the configuration is applied. If a bit is set to 1, its corresponding field uses a specified value. If a bit is set to 0, its corresponding field uses the default value. See the individual field description for configurable mask bits.
stage	KmlDssSolveStage	Back substitution phase. The options are as follows: KMLDSS_SOLVE_ALL: full-phase back substitution, including iterative refinement. This is the default option. KMLDSS_SOLVE_FORWARD: forward substitution only. KMLDSS_SOLVE_DIAGONAL: diagonal block solving only. KMLDSS_SOLVE_BACKWARD: backward substitution only. KMLDSS_SOLVE_REFINE: iterative refinement only. Mask bit: KMLDSS_SOLVE_OPTION_SOLVE_STAGE
refineMethod	KmlDssRefineMethod	Iterative refinement method, including: KMLDSS_REFINE_OFF: iterative refinement disabled (default option) KMLDSS_REFINE_CLASSICAL: classical iterative refinement Mask bit: KMLDSS_SOLVE_OPTION_REFINE_METHOD
refineMaxSteps	int32_t	Maximum number of iterative refinement steps, including: The value 0 indicates that the solver automatically determines the value. This is the default value. A value greater than 0 indicates that the maximum number of iterative refinement steps is set by the user. Mask bit: KMLDSS_SOLVE_OPTION_REFINE_MAX_STEP
refineTolerance	double	Residual threshold for iterative refinement, including the following values: The value 0 indicates that the solver automatically determines the value. This is the default value. A value greater than 0 indicates that the threshold is set by the user. Mask bit: KMLDSS_SOLVE_OPTION_REFINE_TOLERANCE If any of the following conditions is met, iteration refinement is terminated immediately: $\text{[math]}$ The number of steps reaches refineMaxSteps. The calculation method of berr is $\text{[math]}$ .

Return Value

Return Value	Type	Description
KMLSS_NO_ERROR	int	Normal execution.
KMLSS_INTERNAL_ERROR	int	Internal error.
KMLSS_NULL_ARGUMENT	int	A null argument exists in {solver, b, x, option}.

Dependencies

#include "kml_dss.h"

Parent topic: Solver Functions