zgtsv(l) [redhat man page]

ZGTSV(l)								 )								  ZGTSV(l)

NAME

       ZGTSV - solve the equation  A*X = B,

SYNOPSIS

       SUBROUTINE ZGTSV( N, NRHS, DL, D, DU, B, LDB, INFO )

	   INTEGER	 INFO, LDB, N, NRHS

	   COMPLEX*16	 B( LDB, * ), D( * ), DL( * ), DU( * )

PURPOSE

       ZGTSV 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'*X = B  may be solved by interchanging the order of the arguments DU and DL.

ARGUMENTS

       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/output) COMPLEX*16 array, dimension (N-1)
	       On  entry,  DL  must  contain  the (n-1) subdiagonal elements of A.  On exit, DL is overwritten by the (n-2) elements of the second
	       superdiagonal of the upper triangular matrix U from the LU factorization of A, in DL(1), ..., DL(n-2).

       D       (input/output) COMPLEX*16 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      (input/output) COMPLEX*16 array, dimension (N-1)
	       On entry, DU must contain the (n-1) superdiagonal elements of A.  On exit, DU is overwritten by the (n-1)  elements  of	the  first
	       superdiagonal of U.

       B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
	       On entry, the N-by-NRHS right hand side matrix B.  On exit, if INFO = 0, the N-by-NRHS 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
	       > 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.

LAPACK version 3.0						   15 June 2000 							  ZGTSV(l)

zgtsv.f(3)							      LAPACK								zgtsv.f(3)

NAME

       zgtsv.f -

SYNOPSIS

   Functions/Subroutines
       subroutine zgtsv (N, NRHS, DL, D, DU, B, LDB, INFO)
	    ZGTSV computes the solution to system of linear equations A * X = B for GT matrices

Function/Subroutine Documentation
   subroutine zgtsv (integerN, integerNRHS, complex*16, dimension( * )DL, complex*16, dimension( * )D, complex*16, dimension( * )DU, complex*16,
       dimension( ldb, * )B, integerLDB, integerINFO)
	ZGTSV computes the solution to system of linear equations A * X = B for GT matrices

       Purpose:

	    ZGTSV  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 COMPLEX*16 array, dimension (N-1)
		     On entry, DL must contain the (n-1) subdiagonal elements of
		     A.
		     On exit, DL is overwritten by the (n-2) elements of the
		     second superdiagonal of the upper triangular matrix U from
		     the LU factorization of A, in DL(1), ..., DL(n-2).

	   D

		     D is COMPLEX*16 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 COMPLEX*16 array, dimension (N-1)
		     On entry, DU must contain the (n-1) superdiagonal elements
		     of A.
		     On exit, DU is overwritten by the (n-1) elements of the first
		     superdiagonal of U.

	   B

		     B is COMPLEX*16 array, dimension (LDB,NRHS)
		     On entry, the N-by-NRHS 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.

       Date:
	   September 2012

       Definition at line 125 of file zgtsv.f.

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

Version 3.4.2							  Tue Sep 25 2012							zgtsv.f(3)