KmlScadss(SPD/HPD)Solve?I

Solve LL^T x = b or LL^H x = b.

Interface Definition

C interfaces:

int KmlScadssSpdSolveSI(KmlScaSolverTask **pHandle, int nb, float *x, int ldx, float *b, int ldb);

int KmlScadssSpdSolveDI(KmlScaSolverTask **pHandle, int nb, double *x, int ldx, double *b, int ldb);

int KmlScadssHpdSolveCI(KmlScaSolverTask **pHandle, int nb, kml_complex_float *x, int ldx, kml_complex_float *b, int ldb);

int KmlScadssHpdSolveZI(KmlScaSolverTask **pHandle, int nb, kml_complex_double *x, int ldx, kml_complex_double *b, int ldb);

Parameters

Parameter	Type	Description	Input/Output
pHandle	KmlScasolverTask **	Solver handle, which is a variable passed from a previous step.	Input
nb	int	Number of RHS vectors.	Input
x	float * in KmlScadssSpdSolveSI double * in KmlScadssSpdSolveDI kml_complex_float * in KmlScadssHpdSolveCI kml_complex_double * in KmlScadssHpdSolveZI	Dense vector that stores the solution result. The number of elements is ldxnb. The i-th element of the k-th vector is stored at x[i + k ldx]**.	Output
ldx	int	Leading dimension of x. ldx ≥ max(1, n).	Input
b	float * in KmlScadssSpdSolveSI double * in KmlScadssSpdSolveDI kml_complex_float * in KmlScadssHpdSolveCI kml_complex_double * in KmlScadssHpdSolveZI	Dense vector that stores the RHS. The quantity of elements is ldbnb, and the i-th element of the k-th vector is stored at b[i + k * ldb]*.	Input
ldb	int	Leading dimension of b. ldb ≥ max(1, n).	Input

Return Value

Return Value	Type	Description
KMLSS_NO_ERROR	int	The execution is successful.
KMLSS_NULL_ARGUMENT	int	A null parameter exists in {pHandle, x, b}.
KMLSS_BAD_NB	int	The value of nb is less than or equal to 0.
KMLSS_BAD_HANDLE	int	The format of pHandle is incorrect.
KMLSS_BAD_LDX	int	The value of ldx is out of the valid range.
KMLSS_BAD_LDB	int	The value of ldb is out of the valid range.
KMLSS_INVALID_CALL_ORDER	int	The function execution sequence is incorrect. The previous phase is not Factorize.

Dependencies

#include "kml_scadss.h"

Examples

C interface:

MPI_Init(NULL, NULL);
int size, rank;
MPI_Comm_size(MPI_COMM_WORLD, &size);// Obtain the total number of processes.
MPI_Comm_rank(MPI_COMM_WORLD, &rank);// Obtain the current process rank.

int n = 8;
int ia[9] = {0, 3, 7, 9, 11, 13, 15, 16, 17};
int ja[17] = {0, 3, 4, 1, 2, 3, 5, 2, 7, 3, 6, 4, 5, 5, 7, 6, 7};
double a[17] = {1.0, 1.0, 2.0, 9.0, 2.0, 1.0, -3.0, 3.0, 2.0, 9.0, -5.0, 6.0, 1.0, 4.0, 1.0, 7.0, 2.0};
double b[8] = {4.0, 9.0, 7.0, 6.0, 9.0, 3.0, 2.0, 5.0};
double x[8];
KmlScasolverTask* matrix_handle = NULL;
int ierr = KmlScadssSpdInitDI(&matrix_handle, n, a, ja, ia, MPI_COMM_WORLD);
ierr = KmlScadssSpdAnalyzeDI(&matrix_handle);
ierr = KmlScadssSpdFactorizeDI(&matrix_handle);
int nrhs = 1;
int ldx=n, ldb=n;
ierr = KmlScadssSpdSolveDI(&matrix_handle, nrhs, x, ldx, b, ldb);
if (ierr != 0) {
    printf("\nERROR in KmlScadssSpdSolveDI: %d", ierr);
}
if (rank == 0) {
    for (int i = 0; i < n; i++) {
        printf("%lf ", x[i]);
    }
    printf("\n");
}

Output:

1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000

Parent topic: SCADSS-LLT/LLH (DEPRECATED)