SRC/claqhp.f(3)

🌸 NAME 🌸

Okay bestie, this page is SRC/claqhp.f, and it lives in the Library Functions Manual 🫶. It's all about the CLAQHP routine, no cap.

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

subroutine claqhp (uplo, n, ap, s, scond, amax, equed)

CLAQHP scales a Hermitian matrix stored in packed form. Slay 💅.

👑 Function/Subroutine Documentation 👑

Here's the full signature, character for character:

subroutine claqhp (character uplo, integer n, complex, dimension( * ) ap, real, dimension( * ) s, real scond, real amax, character equed)

CLAQHP scales a Hermitian matrix stored in packed form. Iconic behavior, honestly ✨.

🌟 Purpose 🌟

Bestie, CLAQHP equilibrates a Hermitian matrix A using the scaling factors in the vector S. That's the whole purpose, periodt 💖.

💖 Parameters 💖

🌸 UPLO 🌸

UPLO is CHARACTER*1. It 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. It's the order of the matrix A. N >= 0.

🎀 AP 🎀

AP is COMPLEX array, dimension (N*(N+1)/2).

On entry, it's the upper or lower triangle of the Hermitian matrix A, packed columnwise in a linear array. The j-th column of A is stored in the array AP as follows:

• if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
• if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.

On exit, it's the equilibrated matrix: diag(S) * A * diag(S), in the same storage format as A. No notes, just vibes 💜.

🍓 S 🍓

S is REAL array, dimension (N). These are the scale factors for A.

💜 SCOND 💜

SCOND is REAL. It's the ratio of the smallest S(i) to the largest S(i).

⭐ AMAX ⭐

AMAX is REAL. It's the absolute value of 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• = 'Y': Equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).

🌈 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 125 of file claqhp.f.

🦋 Author 🦋

Generated automatically by Doxygen for LAPACK from the source code.

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And that's the vibe check, bestie 💖: this page is SRC/claqhp.f(3) from LAPACK Version 3.12.0 — the footer didn't give a date, so we're not making one up 🙈. Slay responsibly 💅✨.