DPTTRSV(3)    ScaLAPACK routine of NEC Numeric Library Collection   DPTTRSV(3)



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  fac-
               torization 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



ScaLAPACK routine               31 October 2017                     DPTTRSV(3)