slaqsy(l) [redhat man page]
SLAQSY(l) ) SLAQSY(l) NAME
SLAQSY - equilibrate 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 = 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).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 version 3.0 15 June 2000 SLAQSY(l)
Check Out this Related Man Page
slaqsy.f(3) LAPACK slaqsy.f(3) NAME
slaqsy.f - SYNOPSIS
Functions/Subroutines subroutine slaqsy (UPLO, N, A, LDA, S, SCOND, AMAX, EQUED) SLAQSY Function/Subroutine Documentation subroutine slaqsy (characterUPLO, integerN, real, dimension( lda, * )A, integerLDA, real, dimension( * )S, realSCOND, realAMAX, characterEQUED) SLAQSY Purpose: SLAQSY equilibrates a symmetric matrix A using the scaling factors in the vector S. Parameters: UPLO UPLO is CHARACTER*1 Specifies whether the upper or lower triangular part of the symmetric matrix A is stored. = 'U': Upper triangular = 'L': Lower triangular N N is INTEGER The order of the matrix A. N >= 0. A A is 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 LDA is INTEGER The leading dimension of the array A. LDA >= max(N,1). S S is REAL array, dimension (N) The scale factors for A. SCOND SCOND is REAL Ratio of the smallest S(i) to the largest S(i). AMAX AMAX is REAL Absolute value of largest matrix entry. EQUED EQUED is 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). Internal 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. Author: Univ. of Tennessee Univ. of California Berkeley Univ. of Colorado Denver NAG Ltd. Date: November 2011 Definition at line 134 of file slaqsy.f. Author Generated automatically by Doxygen for LAPACK from the source code. Version 3.4.1 Sun May 26 2013 slaqsy.f(3)