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zlaqge.f(3) LAPACK zlaqge.f(3)

NAME

zlaqge.f -

SYNOPSIS

Functions/Subroutines


subroutine zlaqge (M, N, A, LDA, R, C, ROWCND, COLCND, AMAX, EQUED)
ZLAQGE scales a general rectangular matrix, using row and column scaling factors computed by sgeequ.

Function/Subroutine Documentation

subroutine zlaqge (integerM, integerN, complex*16, dimension( lda, * )A, integerLDA, double precision, dimension( * )R, double precision, dimension( * )C, double precisionROWCND, double precisionCOLCND, double precisionAMAX, characterEQUED)

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

Purpose:


ZLAQGE 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 COMPLEX*16 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= 'B': Both row and column equilibration, i.e., A has been
replaced by diag(R) * A * diag(C).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.

Date:

September 2012

Definition at line 143 of file zlaqge.f.

Author

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Tue Sep 25 2012 Version 3.4.2