DGESV(l)	     LAPACK driver routine (version 1.1)	     DGESV(l)

NAME
  DGESV	- compute the solution to a real system	of linear equations  A * X =
  B,

SYNOPSIS

  SUBROUTINE DGESV( N, NRHS, A,	LDA, IPIV, B, LDB, INFO	)

      INTEGER	    INFO, LDA, LDB, N, NRHS

      INTEGER	    IPIV( * )

      DOUBLE	    PRECISION A( LDA, *	), B( LDB, * )

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

  The LU decomposition with partial pivoting and row interchanges is used to
  factor A as
     A = P * L * U,
  where	P is a permutation matrix, L is	unit lower triangular, and U is	upper
  triangular.  The factored form of A is then used to solve the	system of
  equations A *	X = B.

ARGUMENTS

  N	  (input) INTEGER
	  The number of	linear equations, i.e.,	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.

  A	  (input/output) DOUBLE	PRECISION array, dimension (LDA,N)
	  On entry, the	N-by-N coefficient matrix A.  On exit, the factors L
	  and U	from the factorization A = P*L*U; the unit diagonal elements
	  of L are not stored.

  LDA	  (input) INTEGER
	  The leading dimension	of the array A.	 LDA >=	max(1,N).

  IPIV	  (output) INTEGER array, dimension (N)
	  The pivot indices that define	the permutation	matrix P; row i	of
	  the matrix was interchanged with row IPIV(i).

  B	  (input/output) 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	  (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.  The factorization	has
	  been completed, but the factor U is exactly singular,	so the solu-
	  tion could not be computed.