cgtsv.f(3) [centos man page]

cgtsv.f(3)							      LAPACK								cgtsv.f(3)

NAME

       cgtsv.f -

SYNOPSIS

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

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

       Purpose:

	    CGTSV  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 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 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 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 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 cgtsv.f.

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

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

Check Out this Related Man Page

CGTSV(l)								 )								  CGTSV(l)

NAME

       CGTSV - solve the equation  A*X = B,

SYNOPSIS

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

	   INTEGER	 INFO, LDB, N, NRHS

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

PURPOSE

       CGTSV 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 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 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 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 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 							  CGTSV(l)

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cgtsv.f(3) [centos man page]

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