DQRT12(3)

💖 DQRT12(3) 💖

hey bestie, welcome to the dqrt12.f(3) page from the Library Functions Manual ✨ this one is all about DQRT12, a double precision function that checks singular values like the main character it is 💅

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💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dqrt12.f

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✨ SYNOPSIS ✨

🦋 Functions/Subroutines 🦋

• double precision function DQRT12 (m, n, a, lda, s, work, lwork) — DQRT12 🎀

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🌸 Function/Subroutine Documentation 🌸

double precision function DQRT12 (integer m, integer n, double precision, dimension( lda, * ) a, integer lda, double precision, dimension( * ) s, double precision, dimension( lwork ) work, integer lwork)

DQRT12 💅

🎀 Purpose 🎀

okay so DQRT12 computes the singular values svlues of the upper trapezoid of A(1:M,1:N) and returns the ratio 🔥

     || svlues - s ||/(||s||*eps*max(M,N))

no cap, that formula is the whole vibe check 😭✨

🌈 Parameters 🌈

M

M is INTEGER — the number of rows of the matrix A 🫶

N

N is INTEGER — the number of columns of the matrix A 🫶

A

A is DOUBLE PRECISION array, dimension (LDA,N) — the M-by-N matrix A. Only the upper trapezoid is referenced 👑

LDA

LDA is INTEGER — the leading dimension of the array A 💅

S

S is DOUBLE PRECISION array, dimension (min(M,N)) — the singular values of the matrix A 💖

WORK

WORK is DOUBLE PRECISION array, dimension (LWORK) 🎀

LWORK

LWORK is INTEGER — the length of the array WORK. The condition is:

LWORK >= max(M*N + 4*min(M,N) + max(M,N), M*N+2*MIN( M, N )+4*N)

periodt. That bound is not optional, bestie 💀✨

👑 Author 👑

• Univ. of Tennessee
• Univ. of California Berkeley
• Univ. of Colorado Denver
• NAG Ltd.

Definition at line 88 of file dqrt12.f.

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🎀 Author 🎀

Generated automatically by Doxygen for LAPACK from the source code.

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okay bye bestie 💖 this iconic page is signed off as LAPACK Version 3.12.0, and the footer path is /home/abui...IN/dqrt12.f(3) 🫶 no date in the footer, just those two facts ✨