DPTSV(l)		LAPACK routine (version	1.1)		     DPTSV(l)

NAME
  DPTSV	- compute the solution to a real system	of linear equations A*X	= B,
  where	A is an	N-by-N symmetric positive definite tridiagonal matrix, and X
  and B	are N-by-NRHS matrices

SYNOPSIS

  SUBROUTINE DPTSV( N, NRHS, D,	E, B, LDB, INFO	)

      INTEGER	    INFO, LDB, N, NRHS

      DOUBLE	    PRECISION B( LDB, *	), D( *	), E( *	)

PURPOSE
  DPTSV	computes the solution to a real	system of linear equations A*X = B,
  where	A is an	N-by-N symmetric positive definite tridiagonal matrix, and X
  and B	are N-by-NRHS matrices.

  A is factored	as A = L*D*L**T, and the factored form of A is then used to
  solve	the system of equations.

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.

  D	  (input/output) DOUBLE	PRECISION array, dimension (N)
	  On entry, the	n diagonal elements of the tridiagonal matrix A.  On
	  exit,	the n diagonal elements	of the diagonal	matrix D from the
	  factorization	A = L*D*L**T.

  E	  (input/output) DOUBLE	PRECISION array, dimension (N-1)
	  On entry, the	(n-1) subdiagonal elements of the tridiagonal matrix
	  A.  On exit, the (n-1) subdiagonal elements of the unit bidiagonal
	  factor L from	the L*D*L**T factorization of A.  (E can also be
	  regarded as the superdiagonal	of the unit bidiagonal factor U	from
	  the U**T*D*U factorization of	A.)

  B	  (input/output) DOUBLE	PRECISION array, dimension (LDB,N)
	  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, the leading minor of order	i is not positive
	  definite, and	the solution has not been computed.  The factoriza-
	  tion has not been completed unless i = N.