Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

ID 766686
Date 12/16/2022
Public

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?sytrs_aa

Solves a system of linear equations A * X = B with a symmetric matrix.

call ssytrs_aa(uplo, n, nrhs, A, lda, ipiv, B, ldb, work, lwork, info)

call dsytrs_aa(uplo, n, nrhs, A, lda, ipiv, B, ldb, work, lwork, info)

call csytrs_aa(uplo, n, nrhs, A, lda, ipiv, B, ldb, work, lwork, info)

call zsytrs_aa(uplo, n, nrhs, A, lda, ipiv, B, ldb, work, lwork, info)

Description

?sytrs_aa solves a system of linear equations A * X = B with a symmetric matrix A using the factorization A = U*T*UT or A = L*T*LT computed by ?sytrf_aa.

Input Parameters
uplo

CHARACTER*1

Specifies whether the details of the factorization are stored as an upper or lower triangular matrix.

  • = 'U': Upper triangular; the form is A = U*T*UT.
  • = 'L': Lower triangular; the form is A = L*T*LT.
n

INTEGER

The order of the matrix A. n ≥ 0.

nrhs

INTEGER

The number of right-hand sides; that is, the number of columns of the matrix B. nrhs ≥ 0.

A

REAL for ssytrs_aa

DOUBLE COMPLEX for dsytrs_aa

COMPLEX for csytrs_aa

COMPLEX*16 for zsytrs_aa

Array, dimension (lda,n). Details of factors computed by ?sytrf_aa.

lda

INTEGER

The leading dimension of the array A.lda ≥ max(1, n).

ipiv

INTEGER

Array, dimension (n). Details of the interchanges as computed by ?sytrf_aa.

B

REAL for ssytrs_aa

DOUBLE COMPLEX for dsytrs_aa

COMPLEX for csytrs_aa

COMPLEX*16 for zsytrs_aa

Array, dimension (ldb,nrhs). On entry, the right-hand side matrix B.

ldb

INTEGER

The leading dimension of the array B. ldb ≥ max(1, n).

work

Array, dimension (MAX(1,lwork)).

REAL for ssytrs_aa

DOUBLE COMPLEX for dsytrs_aa

COMPLEX for csytrs_aa

COMPLEX*16 for zsytrs_aa

lwork

INTEGER

The length of the array work.

Output Parameters
B

REAL for ssytrs_aa

DOUBLE COMPLEX for dsytrs_aa

COMPLEX for csytrs_aa

COMPLEX*16 for zsytrs_aa

On exit, the solution matrix X.

info

INTEGER

  • If info = 0: Successful exit.
  • < 0: If info = -i, the ith argument had an illegal value.