SRC/dlaqge.f(3)

NAME
SRC/dlaqge.f

SYNOPSIS

  Functions/Subroutines
subroutine dlaqge (m, n, a, lda, r, c, rowcnd, colcnd, amax, equed)
DLAQGE scales a general rectangular matrix, using row and column scaling factors computed by sgeequ.

Function/Subroutine Documentation

  subroutine dlaqge (integer m, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) r, double precision, dimension( * ) c, double precision rowcnd, double precision colcnd, double precision amax, character equed)

DLAQGE scales a general rectangular matrix, using row and column scaling factors computed by sgeequ.

Purpose:

     DLAQGE equilibrates a general M by N matrix A using the row and
     column scaling factors in the vectors R and C.

Parameters
    M

              M is INTEGER
              The number of rows of the matrix A.  M >= 0.

    N

              N is INTEGER
              The number of columns of the matrix A.  N >= 0.

    A

              A is DOUBLE PRECISION array, dimension (LDA,N)
              On entry, the M by N matrix A.
              On exit, the equilibrated matrix.  See EQUED for the form of
              the equilibrated matrix.

    LDA

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

    R

              R is DOUBLE PRECISION array, dimension (M)
              The row scale factors for A.

    C

              C is DOUBLE PRECISION array, dimension (N)
              The column scale factors for A.

    ROWCND

              ROWCND is DOUBLE PRECISION
              Ratio of the smallest R(i) to the largest R(i).

    COLCND

              COLCND is DOUBLE PRECISION
              Ratio of the smallest C(i) to the largest C(i).

    AMAX

              AMAX is DOUBLE PRECISION
              Absolute value of largest matrix entry.

    EQUED

              EQUED is CHARACTER*1
              Specifies the form of equilibration that was done.
              = 'N':  No equilibration
              = 'R':  Row equilibration, i.e., A has been premultiplied by
                      diag(R).
              = 'C':  Column equilibration, i.e., A has been postmultiplied
                      by diag(C).
              = 'B':  Both row and column equilibration, i.e., A has been
                      replaced by diag(R) * A * diag(C).

Internal Parameters:

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

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 140 of file dlaqge.f.

Author

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