SRC/dgtsv.f(3)             Library Functions Manual             SRC/dgtsv.f(3)

NAME
       SRC/dgtsv.f

SYNOPSIS
   Functions/Subroutines
       subroutine dgtsv (n, nrhs, dl, d, du, b, ldb, info)
            DGTSV computes the solution to system of linear equations A * X =
           B for GT matrices

Function/Subroutine Documentation
   subroutine dgtsv (integer n, integer nrhs, double precision, dimension( * )
       dl, double precision, dimension( * ) d, double precision, dimension( *
       ) du, double precision, dimension( ldb, * ) b, integer ldb, integer
       info)
        DGTSV computes the solution to system of linear equations A * X = B
       for GT matrices

       Purpose:


            DGTSV  solves the equation

               A*X = B,

            where A is an n by n tridiagonal matrix, by Gaussian elimination with
            partial pivoting.

            Note that the equation  A**T*X = B  may be solved by interchanging the
            order of the arguments DU and DL.

       Parameters
           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of right hand sides, i.e., the number of columns
                     of the matrix B.  NRHS >= 0.

           DL

                     DL is DOUBLE PRECISION array, dimension (N-1)
                     On entry, DL must contain the (n-1) sub-diagonal elements of
                     A.

                     On exit, DL is overwritten by the (n-2) elements of the
                     second super-diagonal of the upper triangular matrix U from
                     the LU factorization of A, in DL(1), ..., DL(n-2).

           D

                     D is DOUBLE PRECISION array, dimension (N)
                     On entry, D must contain the diagonal elements of A.

                     On exit, D is overwritten by the n diagonal elements of U.

           DU

                     DU is DOUBLE PRECISION array, dimension (N-1)
                     On entry, DU must contain the (n-1) super-diagonal elements
                     of A.

                     On exit, DU is overwritten by the (n-1) elements of the first
                     super-diagonal of U.

           B

                     B is DOUBLE PRECISION array, dimension (LDB,NRHS)
                     On entry, the N by NRHS matrix of right hand side matrix B.
                     On exit, if INFO = 0, the N by NRHS solution matrix X.

           LDB

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

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value
                     > 0: if INFO = i, U(i,i) is exactly zero, and the solution
                          has not been computed.  The factorization has not been
                          completed unless i = N.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 126 of file dgtsv.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                  SRC/dgtsv.f(3)