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

NAME

       LAPACK-3  - equilibrates a symmetric band matrix A using the scaling factors in the vector
       S

SYNOPSIS

       SUBROUTINE ZLAQSB( UPLO, N, KD, AB, LDAB, S, SCOND, AMAX, EQUED )

           CHARACTER      EQUED, UPLO

           INTEGER        KD, LDAB, N

           DOUBLE         PRECISION AMAX, SCOND

           DOUBLE         PRECISION S( * )

           COMPLEX*16     AB( LDAB, * )

PURPOSE

       ZLAQSB equilibrates a symmetric band matrix A using the scaling factors in the vector S.

ARGUMENTS

        UPLO    (input) CHARACTER*1
                Specifies whether the upper or lower triangular part of the
                symmetric matrix A is stored.
                = 'U':  Upper triangular
                = 'L':  Lower triangular

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

        KD      (input) INTEGER
                The number of super-diagonals of the matrix A if UPLO = 'U',
                or the number of sub-diagonals if UPLO = 'L'.  KD >= 0.

        AB      (input/output) COMPLEX*16 array, dimension (LDAB,N)
                On entry, the upper or lower triangle of the symmetric band
                matrix A, stored in the first KD+1 rows of the array.  The
                j-th column of A is stored in the j-th column of the array AB
                as follows:
                if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j;
                if UPLO = 'L', AB(1+i-j,j)    = A(i,j) for j<=i<=min(n,j+kd).
                On exit, if INFO = 0, the triangular factor U or L from the
                Cholesky factorization A = U**T *U or A = L*L**T of the band
                matrix A, in the same storage format as A.

        LDAB    (input) INTEGER
                The leading dimension of the array AB.  LDAB >= KD+1.

        S       (input) DOUBLE PRECISION array, dimension (N)
                The scale factors for A.

        SCOND   (input) DOUBLE PRECISION
                Ratio of the smallest S(i) to the largest S(i).

        AMAX    (input) DOUBLE PRECISION
                Absolute value of largest matrix entry.

        EQUED   (output) CHARACTER*1
                Specifies whether or not equilibration was done.
                = 'N':  No equilibration.
                = 'Y':  Equilibration was done, i.e., A has been replaced by
                diag(S) * A * diag(S).

PARAMETERS

        THRESH is a threshold value used to decide if scaling should be done
        based on the ratio of the scaling factors.  If SCOND < THRESH,
        scaling is done.
        LARGE and SMALL are threshold values used to decide if scaling should
        be done based on the absolute size of the largest matrix element.
        If AMAX > LARGE or AMAX < SMALL, scaling is done.

 LAPACK auxiliary routine (version 3.3.1)   April 2011                            ZLAQSB(3lapack)