DragonFly On-Line Manual Pages

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

SYNOPSIS
       SUBROUTINE SPTTRSV( TRANS, N, NRHS, D, E, B, LDB, INFO )
           CHARACTER TRANS
           INTEGER INFO, LDB, N, NRHS
           REAL D( * )
           REAL B( LDB, * ), E( * )

PURPOSE
       SPTTRSV 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 SPTTRF).

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 SPTTRF.

       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 SPTTRF (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

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