/home/abui.../sqrt01p.f(3)

🌸 NAME 🌸

Okay so bestie, this page is for /home/abui.../sqrt01p.f(3) — and the manual name is Library Functions Manual. The name itself is this entire absolute path:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/sqrt01p.f

It’s giving “full path realness,” no cap.

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine SQRT01P (m, n, a, af, q, r, lda, tau, work, lwork, rwork,
    result)
    SQRT01P

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💖 Function/Subroutine Documentation 💖

subroutine SQRT01P (integer m, integer n, real, dimension( lda, * ) a, real,
    dimension( lda, * ) af, real, dimension( lda, * ) q, real, dimension(
    lda, * ) r, integer lda, real, dimension( * ) tau, real, dimension(
    lwork ) work, integer lwork, real, dimension( * ) rwork, real,
    dimension( * ) result)
    SQRT01P

🦋 Purpose 🦋

It’s literally in Fortran comment markers, so here they are, preserved exactly:

!>
!> SQRT01P tests SGEQRFP, which computes the QR factorization of an m-by-n
!> matrix A, and partially tests SORGQR which forms the m-by-m
!> orthogonal matrix Q.
!>
!> SQRT01P compares R with Q'*A, and checks that Q is orthogonal.
!>

🎀 Parameters 🎀

• M — M is INTEGER. It’s the number of rows of the matrix A. Condition: M >= 0. Periodt.
• N — N is INTEGER. It’s the number of columns of the matrix A. Condition: N >= 0. Slay.
• A — A is REAL array, dimension (LDA,N). This is the m-by-n matrix A.
• AF — AF is REAL array, dimension (LDA,N). It holds details of the QR factorization of A, as returned by SGEQRFP. See SGEQRFP for further details.
• Q — Q is REAL array, dimension (LDA,M). This is the m-by-m orthogonal matrix Q.
• R — R is REAL array, dimension (LDA,max(M,N)).
• LDA — LDA is INTEGER. It’s the leading dimension of the arrays A, AF, Q and R. Condition: LDA >= max(M,N). Don’t fumble that one, bestie.
• TAU — TAU is REAL array, dimension (min(M,N)). These are the scalar factors of the elementary reflectors, as returned by SGEQRFP.
• WORK — WORK is REAL array, dimension (LWORK).
• LWORK — LWORK is INTEGER. It’s the dimension of the array WORK.
• RWORK — RWORK is REAL array, dimension (M).
• RESULT — RESULT is REAL array, dimension (2). These are the test ratios:
  • RESULT(1) = norm( R - Q'*A ) / ( M * norm(A) * EPS )
  • RESULT(2) = norm( I - Q'*Q ) / ( M * EPS )

This is the part where the function is basically doing a vibe check on Q and R. It compares R with Q'*A, and checks that Q is orthogonal. Iconic behavior, honestly.

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💜 Author 💜

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

Definition at line 124 of file sqrt01p.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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xoxo, your LAPACK bestie 💅✨ — LAPACK Version 3.12.0 — /home/abui.../sqrt01p.f(3) 🫶🎀