ZPTTS2(3)      LAPACK routine of NEC Numeric Library Collection      ZPTTS2(3)



NAME
       ZPTTS2

SYNOPSIS
       SUBROUTINE ZPTTS2 (IUPLO, N, NRHS, D, E, B, LDB)



PURPOSE
            ZPTTS2 solves a tridiagonal system of the form
               A * X = B
            using the factorization A = U**H *D*U or A = L*D*L**H computed by ZPTTRF.
            D is a diagonal matrix specified in the vector D, U (or L) is a unit
            bidiagonal matrix whose superdiagonal (subdiagonal) is specified in
            the vector E, and X and B are N by NRHS matrices.




ARGUMENTS
           IUPLO     (input)
                     IUPLO is INTEGER
                     Specifies the form of the factorization and whether the
                     vector E is the superdiagonal of the upper bidiagonal factor
                     U or the subdiagonal of the lower bidiagonal factor L.
                     = 1:  A = U**H *D*U, E is the superdiagonal of U
                     = 0:  A = L*D*L**H, E is the subdiagonal of L

           N         (input)
                     N is INTEGER
                     The order of the tridiagonal 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.

           D         (input)
                     D is DOUBLE PRECISION array, dimension (N)
                     The n diagonal elements of the diagonal matrix D from the
                     factorization A = U**H *D*U or A = L*D*L**H.

           E         (input)
                     E is COMPLEX*16 array, dimension (N-1)
                     If IUPLO = 1, the (n-1) superdiagonal elements of the unit
                     bidiagonal factor U from the factorization A = U**H*D*U.
                     If IUPLO = 0, the (n-1) subdiagonal elements of the unit
                     bidiagonal factor L from the factorization A = L*D*L**H.

           B         (input/output)
                     B is DOUBLE PRECISION array, dimension (LDB,NRHS)
                     On entry, the right hand side vectors B for the system of
                     linear equations.
                     On exit, the solution vectors, X.

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



LAPACK routine                  31 October 2017                      ZPTTS2(3)