NAME

       DPTTRSV - solve one of the triangular systems  L**T* X = B, or L * X = B,

SYNOPSIS

       SUBROUTINE DPTTRSV( TRANS, N, NRHS, D, E, B, LDB, INFO )

           CHARACTER       TRANS

           INTEGER         INFO, LDB, N, NRHS

           DOUBLE          PRECISION D( * )

           DOUBLE          PRECISION B( LDB, * ), E( * )

PURPOSE

       DPTTRSV solves one of the triangular systems
          L**T* X = B, or  L * X = B, where L is the Cholesky factor of a Hermitian positive
       definite tridiagonal matrix A such that
       A = L*D*L**H (computed by DPTTRF).

ARGUMENTS

       TRANS   (input) CHARACTER
               Specifies the form of the system of equations:
               = 'N':  L * X = B     (No transpose)
               = 'T':  L**T * X = B  (Transpose)

       N       (input) INTEGER
               The order of the tridiagonal 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.

       D       (input) REAL array, dimension (N)
               The n diagonal elements of the diagonal matrix D from the  factorization  computed
               by DPTTRF.

       E       (input) COMPLEX array, dimension (N-1)
               The  (n-1)  off-diagonal  elements  of  the unit bidiagonal factor U or L from the
               factorization computed by DPTTRF (see UPLO).

       B       (input/output) COMPLEX 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