CLAQSY(3)

💅 CLAQSY(3) 💅

okay so this is CLAQSY(3) from the Library Functions Manual — the LAPACK cutie that scales a symmetric/Hermitian matrix using scaling factors computed by spoequ. She’s giving very specific linear-algebra main character energy, and honestly? Obsessed 🫶✨

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🌸 NAME 🌸

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/claqsy.f

yes bestie, that whole long path is the name. It’s giving source-file realness 💅

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

• subroutine CLAQSY (uplo, n, a, lda, s, scond, amax, equed) — CLAQSY scales a symmetric/Hermitian matrix, using scaling factors computed by spoequ.

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🦋 Function/Subroutine Documentation 🦋

Here’s the full signature, character-for-character, no cap:

subroutine CLAQSY (character uplo, integer n, complex, dimension( lda, * )
       a, integer lda, real, dimension( * ) s, real scond, real amax, character
       equed)

CLAQSY scales a symmetric/Hermitian matrix, using scaling factors computed by spoequ.

🌟 Purpose 🌟

CLAQSY 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 COMPLEX 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  • = 'Y': equilibration was done, i.e., A has been replaced by diag(S) * A * diag(S).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.

Definition at line 133 of file claqsy.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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xoxo, this page is LAPACK Version 3.12.0, straight from /home/abui...RC/claqsy.f(3) — mwah 💋✨