CSYTRS2(3)     LAPACK routine of NEC Numeric Library Collection     CSYTRS2(3)



NAME
       CSYTRS2

SYNOPSIS
       SUBROUTINE CSYTRS2 (UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK, INFO)



PURPOSE
            CSYTRS2 solves a system of linear equations A*X = B with a COMPLEX
            symmetric matrix A using the factorization A = U*D*U**T or
            A = L*D*L**T computed by CSYTRF and converted by CSYCONV.




ARGUMENTS
           UPLO      (input)
                     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*D*U**T;
                     = 'L':  Lower triangular, form is A = L*D*L**T.

           N         (input)
                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           NRHS      (input)
                     NRHS is INTEGER
                     The number of right hand sides, i.e., the number of columns
                     of the matrix B.  NRHS >= 0.

           A         (input)
                     A is COMPLEX array, dimension (LDA,N)
                     The block diagonal matrix D and the multipliers used to
                     obtain the factor U or L as computed by CSYTRF.

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

           IPIV      (input)
                     IPIV is INTEGER array, dimension (N)
                     Details of the interchanges and the block structure of D
                     as determined by CSYTRF.

           B         (input/output)
                     B is COMPLEX array, dimension (LDB,NRHS)
                     On entry, the right hand side matrix B.
                     On exit, the solution matrix X.

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

           WORK      (output)
                     WORK is COMPLEX array, dimension (N)

           INFO      (output)
                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value



LAPACK routine                  31 October 2017                     CSYTRS2(3)