.TH CLAQSP 1 "November 2006" " LAPACK auxiliary routine (version 3.1) " " LAPACK auxiliary routine (version 3.1) " .SH NAME CLAQSP - a symmetric matrix A using the scaling factors in the vector S .SH SYNOPSIS .TP 19 SUBROUTINE CLAQSP( UPLO, N, AP, S, SCOND, AMAX, EQUED ) .TP 19 .ti +4 CHARACTER EQUED, UPLO .TP 19 .ti +4 INTEGER N .TP 19 .ti +4 REAL AMAX, SCOND .TP 19 .ti +4 REAL S( * ) .TP 19 .ti +4 COMPLEX AP( * ) .SH PURPOSE CLAQSP equilibrates a symmetric matrix A using the scaling factors in the vector S. .SH ARGUMENTS .TP 8 UPLO (input) CHARACTER*1 Specifies whether the upper or lower triangular part of the symmetric matrix A is stored. = \(aqU\(aq: Upper triangular .br = \(aqL\(aq: Lower triangular .TP 8 N (input) INTEGER The order of the matrix A. N >= 0. .TP 8 AP (input/output) COMPLEX array, dimension (N*(N+1)/2) On entry, the upper or lower triangle of the symmetric matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows: if UPLO = \(aqU\(aq, AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j; if UPLO = \(aqL\(aq, AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n. On exit, the equilibrated matrix: diag(S) * A * diag(S), in the same storage format as A. .TP 8 S (input) REAL array, dimension (N) The scale factors for A. .TP 8 SCOND (input) REAL Ratio of the smallest S(i) to the largest S(i). .TP 8 AMAX (input) REAL Absolute value of largest matrix entry. .TP 8 EQUED (output) CHARACTER*1 Specifies whether or not equilibration was done. = \(aqN\(aq: No equilibration. .br = \(aqY\(aq: Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S). .SH 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.