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

NAME

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

SYNOPSIS

       SUBROUTINE SLAQSY( UPLO, N, A, LDA, S, SCOND, AMAX, EQUED )

           CHARACTER      EQUED, UPLO

           INTEGER        LDA, N

           REAL           AMAX, SCOND

           REAL           A( LDA, * ), S( * )

PURPOSE

       SLAQSY equilibrates a symmetric 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.

        A       (input/output) REAL array, dimension (LDA,N)
                On entry, the symmetric matrix A.  If UPLO = 'U', the leading
                n by n upper triangular part of A contains the upper
                triangular part of the matrix A, and the strictly lower
                triangular part of A is not referenced.  If UPLO = 'L', the
                leading n by n lower triangular part of A contains the lower
                triangular part of the matrix A, and the strictly upper
                triangular part of A is not referenced.
                On exit, if EQUED = 'Y', the equilibrated matrix:
                diag(S) * A * diag(S).

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

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

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

        AMAX    (input) REAL
                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                = 'Y':  Equilibration was done, i.e., A has been replaced by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 3.2)     April 2011                            SLAQSY(3lapack)