dsytrs(3F)

NAME
     DSYTRS - solve a system of linear equations A*X = B with a real symmetric
     matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by
     DSYTRF

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

         CHARACTER      UPLO

         INTEGER        INFO, LDA, LDB, N, NRHS

         INTEGER        IPIV( * )

         DOUBLE         PRECISION A( LDA, * ), B( LDB, * )

PURPOSE
     DSYTRS solves a system of linear equations A*X = B with a real symmetric
     matrix A using the factorization A = U*D*U**T or A = L*D*L**T computed by
     DSYTRF.


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

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

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

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

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

     B       (input/output) DOUBLE PRECISION array, dimension (LDB,NRHS)
             On entry, the right hand side matrix B.  On exit, the solution
             matrix X.
     LDB     (input) INTEGER
             The leading dimension of the array B.  LDB >= max(1,N).

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