Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3  - estimates 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 factorization computed by SGBTRF.
        An estimate is obtained for norm(inv(A)), and the reciprocal of the
        condition number 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
                interchanged 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

 LAPACK routine (version 3.3.1)             April 2011                            SGBCON(3lapack)