cgttrs(3F)

NAME
     CGTTRS - solve one of the systems of equations  A * X = B, A**T * X = B,
     or A**H * X = B,

SYNOPSIS
     SUBROUTINE CGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B, LDB, INFO )

         CHARACTER      TRANS

         INTEGER        INFO, LDB, N, NRHS

         INTEGER        IPIV( * )

         COMPLEX        B( LDB, * ), D( * ), DL( * ), DU( * ), DU2( * )

PURPOSE
     CGTTRS solves one of the systems of equations
        A * X = B,  A**T * X = B,  or  A**H * X = B, with a tridiagonal matrix
     A using the LU factorization computed by CGTTRF.


ARGUMENTS
     TRANS   (input) CHARACTER
             Specifies the form of the system of equations:
             = 'N':  A * X = B     (No transpose)
             = 'T':  A**T * X = B  (Transpose)
             = 'C':  A**H * X = B  (Conjugate transpose)

     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.

     DL      (input) COMPLEX array, dimension (N-1)
             The (n-1) multipliers that define the matrix L from the LU
             factorization of A.

     D       (input) COMPLEX array, dimension (N)
             The n diagonal elements of the upper triangular matrix U from the
             LU factorization of A.

     DU      (input) COMPLEX array, dimension (N-1)
             The (n-1) elements of the first superdiagonal of U.

     DU2     (input) COMPLEX array, dimension (N-2)
             The (n-2) elements of the second superdiagonal of U.

     IPIV    (input) INTEGER array, dimension (N)
             The pivot indices; for 1 <= i <= n, row i of the matrix was
             interchanged with row IPIV(i).  IPIV(i) will always be either i
             or i+1; IPIV(i) = i indicates a row interchange was not required.

     B       (input/output) COMPLEX array, dimension (LDB,NRHS)
             On entry, the right hand side matrix B.  On exit, B is
             overwritten by 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