SRC/zlaqhe.f(3)

💖 NAME 💖

okay so this page is from SRC/zlaqhe.f(3), and it lives in the Library Functions Manual. It's literally all about zlaqhe: the subroutine that scales a Hermitian matrix. slay. 👑

✨ 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. that's the main character energy right there. ✨

🎀 Purpose 🎀

ZLAQHE equilibrates a Hermitian matrix A using the scaling factors in the vector S. that's the whole purpose, bestie — the matrix is getting its equilibrated moment. 💅

💜 Parameters 💜

• UPLO — UPLO is CHARACTER*1, and it tells you whether the upper or lower triangular part of the Hermitian matrix A is stored. = 'U': Upper triangular. = 'L': Lower triangular. pick your triangle, no cap. 💖
• N — N is INTEGER. it's the order of the matrix A, and N >= 0. periodt.
• A — A is COMPLEX*16 array, dimension (LDA,N). on entry, it's 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', it's the equilibrated matrix: diag(S) * A * diag(S). iconic behavior.

• LDA — LDA is INTEGER. it's the leading dimension of the array A, and LDA >= max(N,1). don't forget the max, bestie. 😭
• S — S is DOUBLE PRECISION array, dimension (N). these are the scale factors for A. 💫
• SCOND — SCOND is DOUBLE PRECISION. it's the ratio of the smallest S(i) to the largest S(i). math girlies rise. 🌸
• AMAX — AMAX is DOUBLE PRECISION. it's the absolute value of the largest matrix entry. 🔥
• EQUED — EQUED is CHARACTER*1. it 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 = 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S). that's the tea. ☕

🧚 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.

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and that's the footer tea, bestie: LAPACK, Version 3.12.0, source SRC/zlaqhe.f(3). the date slot is not giving a date on this page, so we're not inventing one — periodt. 💅💖