Provided by: liblapack-doc_3.3.1-1_all
LAPACK-3 - equilibrates a general M by N matrix A using the row and column scaling factors in the vectors R and C
SUBROUTINE CLAQGE( M, N, A, LDA, R, C, ROWCND, COLCND, AMAX, EQUED ) CHARACTER EQUED INTEGER LDA, M, N REAL AMAX, COLCND, ROWCND REAL C( * ), R( * ) COMPLEX A( LDA, * )
CLAQGE equilibrates a general M by N matrix A using the row and column scaling factors in the vectors R and C.
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. A (input/output) COMPLEX 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 (input) INTEGER The leading dimension of the array A. LDA >= max(M,1). R (input) REAL array, dimension (M) The row scale factors for A. C (input) REAL array, dimension (N) The column scale factors for A. ROWCND (input) REAL Ratio of the smallest R(i) to the largest R(i). COLCND (input) REAL Ratio of the smallest C(i) to the largest C(i). AMAX (input) REAL 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 postmultiplied by diag(C). = 'B': Both row and column equilibration, i.e., A has been replaced by diag(R) * A * diag(C).
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 auxiliary routine (version 3.2) April 2011 CLAQGE(3lapack)