SGBCON(l)		LAPACK routine (version	1.1)		    SGBCON(l)

NAME
  SGBCON - estimate the	reciprocal of the condition number of a	real general
  band matrix A, in either the 1-norm or the infinity-norm,

SYNOPSIS

  SUBROUTINE SGBCON( NORM, N, KL, KU, AB, LDAB,	IPIV, ANORM, RCOND, WORK,
		     IWORK, INFO )

      CHARACTER	     NORM

      INTEGER	     INFO, KL, KU, LDAB, N

      REAL	     ANORM, RCOND

      INTEGER	     IPIV( * ),	IWORK( * )

      REAL	     AB( LDAB, * ), WORK( * )

PURPOSE
  SGBCON estimates the reciprocal of the condition number of a real general
  band matrix A, in either the 1-norm or the infinity-norm, using the LU fac-
  torization computed by SGBTRF.

  An estimate is obtained for norm(inv(A)), and	RCOND is computed as
     RCOND = 1 / ( norm(A) * norm(inv(A)) ).

ARGUMENTS

  NORM	  (input) CHARACTER*1
	  Specifies whether the	1-norm condition number	or the infinity-norm
	  condition number is required:
	  = '1'	or 'O':	 1-norm;
	  = 'I':	 Infinity-norm.

  N	  (input) INTEGER
	  The order of the matrix A.  N	>= 0.

  KL	  (input) INTEGER
	  The number of	subdiagonals within the	band of	A.  KL >= 0.

  KU	  (input) INTEGER
	  The number of	superdiagonals within the band of A.  KU >= 0.

  AB	  (input) REAL array, dimension	(LDAB,N)
	  Details of the LU factorization of the band matrix A,	as computed
	  by SGBTRF.  U	is stored as an	upper triangular band matrix with
	  KL+KU	superdiagonals in rows 1 to KL+KU+1, and the multipliers used
	  during the factorization are stored in rows KL+KU+2 to 2*KL+KU+1.

  LDAB	  (input) INTEGER
	  The leading dimension	of the array AB.  LDAB >= 2*KL+KU+1.

  IPIV	  (input) INTEGER array, dimension (N)
	  The pivot indices; for 1 <= i	<= N, row i of the matrix was inter-
	  changed with row IPIV(i).

  ANORM	  (input) REAL
	  If NORM = '1'	or 'O',	the 1-norm of the original matrix A.  If NORM
	  = 'I', the infinity-norm of the original matrix A.

  RCOND	  (output) REAL
	  The reciprocal of the	condition number of the	matrix A, computed as
	  RCOND	= 1/(norm(A) * norm(inv(A))).

  WORK	  (workspace) REAL array, dimension (3*N)

  IWORK	  (workspace) INTEGER array, dimension (N)

  INFO	  (output) INTEGER
	  = 0:	successful exit
	  < 0: if INFO = -i, the i-th argument had an illegal value