SRC/zlaqhe.f(3) Library Functions Manual SRC/zlaqhe.f(3) NAME SRC/zlaqhe.f SYNOPSIS Functions/Subroutines subroutine zlaqhe (uplo, n, a, lda, s, scond, amax, equed) ZLAQHE scales a Hermitian matrix. Function/Subroutine Documentation subroutine zlaqhe (character uplo, integer n, complex*16, dimension( lda, * ) a, integer lda, double precision, dimension( * ) s, double precision scond, double precision amax, character equed) ZLAQHE scales a Hermitian matrix. Purpose: ZLAQHE equilibrates a Hermitian 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 Hermitian 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 COMPLEX*16 array, dimension (LDA,N) On entry, the Hermitian 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 DOUBLE PRECISION array, dimension (N) The scale factors for A. SCOND SCOND is DOUBLE PRECISION Ratio of the smallest S(i) to the largest S(i). AMAX AMAX is DOUBLE PRECISION 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 = 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).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. Definition at line 133 of file zlaqhe.f. Author Generated automatically by Doxygen for LAPACK from the source code. LAPACK Version 3.12.0 SRC/zlaqhe.f(3)