redhat man page for zlaqgb

Query: zlaqgb

OS: redhat

Section: l

Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar

ZLAQGB(l)								 )								 ZLAQGB(l)

NAME
ZLAQGB - equilibrate a general M by N band matrix A with KL subdiagonals and KU superdiagonals using the row and scaling factors in the vectors R and C
SYNOPSIS
SUBROUTINE ZLAQGB( M, N, KL, KU, AB, LDAB, R, C, ROWCND, COLCND, AMAX, EQUED ) CHARACTER EQUED INTEGER KL, KU, LDAB, M, N DOUBLE PRECISION AMAX, COLCND, ROWCND DOUBLE PRECISION C( * ), R( * ) COMPLEX*16 AB( LDAB, * )
PURPOSE
ZLAQGB equilibrates a general M by N band matrix A with KL subdiagonals and KU superdiagonals using the row and scaling factors in the vec- tors R and C.
ARGUMENTS
M (input) INTEGER The number of rows of the matrix A. M >= 0. N (input) INTEGER The number of columns 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/output) COMPLEX*16 array, dimension (LDAB,N) On entry, the matrix A in band storage, in rows 1 to KL+KU+1. The j-th column of A is stored in the j-th column of the array AB as follows: AB(ku+1+i-j,j) = A(i,j) for max(1,j-ku)<=i<=min(m,j+kl) On exit, the equilibrated matrix, in the same storage format as A. See EQUED for the form of the equilibrated matrix. LDAB (input) INTEGER The leading dimension of the array AB. LDA >= KL+KU+1. R (output) DOUBLE PRECISION array, dimension (M) The row scale factors for A. C (output) DOUBLE PRECISION array, dimension (N) The column scale factors for A. ROWCND (output) DOUBLE PRECISION Ratio of the smallest R(i) to the largest R(i). COLCND (output) DOUBLE PRECISION Ratio of the smallest C(i) to the largest C(i). AMAX (input) DOUBLE PRECISION Absolute value of largest matrix entry. EQUED (output) 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 postmulti- plied by diag(C). = 'B': Both row and column equilibration, i.e., A has been replaced by diag(R) * A * diag(C).
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. LAPACK version 3.0 15 June 2000 ZLAQGB(l)
Related Man Pages
claqgb(l) - redhat
dlaqgb.f(3) - debian
zlaqgb.f(3) - debian
dlaqgb.f(3) - centos
zlaqgb.f(3) - centos
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