PLASMA
2.8.0
PLASMA - Parallel Linear Algebra for Scalable Multi-core Architectures
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int PLASMA_sposv | ( | PLASMA_enum | uplo, |
int | N, | ||
int | NRHS, | ||
float * | A, | ||
int | LDA, | ||
float * | B, | ||
int | LDB | ||
) |
PLASMA_sposv - Computes the solution to a system of linear equations A * X = B, where A is an N-by-N symmetric positive definite (or Hermitian positive definite in the complex case) matrix and X and B are N-by-NRHS matrices. The Cholesky decomposition is used to factor A as
\[ A = \{_{L\times L^H, if uplo = PlasmaLower}^{U^H\times U, if uplo = PlasmaUpper} \]
where U is an upper triangular matrix and L is a lower triangular matrix. The factored form of A is then used to solve the system of equations A * X = B.
[in] | uplo | Specifies whether the matrix A is upper triangular or lower triangular: = PlasmaUpper: Upper triangle of A is stored; = PlasmaLower: Lower triangle of A is stored. |
[in] | N | The number of linear equations, i.e., the order of the matrix A. N >= 0. |
[in] | NRHS | The number of right hand sides, i.e., the number of columns of the matrix B. NRHS >= 0. |
[in,out] | A | On entry, the symmetric positive definite (or Hermitian) matrix A. If uplo = PlasmaUpper, the leading N-by-N upper triangular part of A contains the upper triangular part of the matrix A, and the strictly lower triangular part of A is not referenced. If UPLO = 'L', the leading N-by-N lower triangular part of A contains the lower triangular part of the matrix A, and the strictly upper triangular part of A is not referenced. On exit, if return value = 0, the factor U or L from the Cholesky factorization A = U**T*U or A = L*L**T. |
[in] | LDA | The leading dimension of the array A. LDA >= max(1,N). |
[in,out] | B | On entry, the N-by-NRHS right hand side matrix B. On exit, if return value = 0, the N-by-NRHS solution matrix X. |
[in] | LDB | The leading dimension of the array B. LDB >= max(1,N). |
PLASMA_SUCCESS | successful exit |
<0 | if -i, the i-th argument had an illegal value |
>0 | if i, the leading minor of order i of A is not positive definite, so the factorization could not be completed, and the solution has not been computed. |