DSYTRS_AA solves a system of linear equations A*X = B with a real


 symmetric matrix A using the factorization A = U*T*U**T or


 A = L*T*L**T computed by DSYTRF_AA.

UPLO

          UPLO is CHARACTER*1


          Specifies whether the details of the factorization are stored


          as an upper or lower triangular matrix.


          = 'U':  Upper triangular, form is A = U*T*U**T;


          = 'L':  Lower triangular, form is A = L*T*L**T.

N

          N is INTEGER


          The order of the matrix A.  N >= 0.

NRHS

          NRHS is INTEGER


          The number of right hand sides, i.e., the number of columns


          of the matrix B.  NRHS >= 0.

A

          A is DOUBLE PRECISION array, dimension (LDA,N)


          Details of factors computed by DSYTRF_AA.

LDA

          LDA is INTEGER


          The leading dimension of the array A.  LDA >= max(1,N).

IPIV

          IPIV is INTEGER array, dimension (N)


          Details of the interchanges as computed by DSYTRF_AA.

B

          B is DOUBLE PRECISION array, dimension (LDB,NRHS)


          On entry, the right hand side matrix B.


          On exit, the solution matrix X.

LDB

          LDB is INTEGER


          The leading dimension of the array B.  LDB >= max(1,N).

WORK

          WORK is DOUBLE array, dimension (MAX(1,LWORK))

LWORK

          LWORK is INTEGER, LWORK >= MAX(1,3*N-2).


 aram[out]


INFO


 


          INFO is INTEGER


          = 0:  successful exit


          < 0:  if INFO = -i, the i-th argument had an illegal value

Univ. of Tennessee

Univ. of California Berkeley

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NAG Ltd.

November 2017