DPTSV(1)		 LAPACK routine (version 3.2)		      DPTSV(1)

NAME
       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

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  bidiago‐
	       nal factor U from the U**T*D*U factorization of A.)

       B       (input/output) DOUBLE PRECISION 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, the leading minor of order i is not positive
	       definite,  and the solution has not been computed.  The factor‐
	       ization has not been completed unless i = N.

 LAPACK routine (version 3.2)	 November 2008			      DPTSV(1)

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