/home/abui.../dqrt01p.f(3)

💖 NAME 💖

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/TESTING/LIN/dqrt01p.f

okay so this page is from a Library Functions Manual, and the title path up top is /home/abui.../dqrt01p.f(3). The NAME section is literally that long file path above — that’s the file this whole page is about, bestie 💅

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✨ SYNOPSIS ✨

🫶 Functions/Subroutines 🫶

• subroutine DQRT01P (m, n, a, af, q, r, lda, tau, work, lwork, rwork, result) — DQRT01P

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🎀 Function/Subroutine Documentation 🎀

💅 subroutine DQRT01P 💅

subroutine DQRT01P (integer m, integer n, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) q, double precision, dimension( lda, * ) r, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( * ) result)

DQRT01P

🌸 Purpose 🌸

Bestie, here’s the whole point: DQRT01P tests DGEQRFP, which computes the QR factorization of an m-by-n matrix A, and partially tests DORGQR which forms the m-by-m orthogonal matrix Q. ✨

DQRT01P compares R with Q'*A, and checks that Q is orthogonal. No cap, that’s the entire vibe. 🫶

💅 Parameters 💅

• M — M is INTEGER; the number of rows of the matrix A. M >= 0.
• N — N is INTEGER; the number of columns of the matrix A. N >= 0.
• A — A is DOUBLE PRECISION array, dimension (LDA,N); the m-by-n matrix A.
• AF — AF is DOUBLE PRECISION array, dimension (LDA,N); details of the QR factorization of A, as returned by DGEQRFP. See DGEQRFP for further details.
• Q — Q is DOUBLE PRECISION array, dimension (LDA,M); the m-by-m orthogonal matrix Q.
• R — R is DOUBLE PRECISION array, dimension (LDA,max(M,N)).
• LDA — LDA is INTEGER; the leading dimension of the arrays A, AF, Q and R. LDA >= max(M,N).
• TAU — TAU is DOUBLE PRECISION array, dimension (min(M,N)); the scalar factors of the elementary reflectors, as returned by DGEQRFP.
• WORK — WORK is DOUBLE PRECISION array, dimension (LWORK).
• LWORK — LWORK is INTEGER; the dimension of the array WORK.
• RWORK — RWORK is DOUBLE PRECISION array, dimension (M).
• RESULT — RESULT is DOUBLE PRECISION array, dimension (2). The test ratios:
  • RESULT(1) = norm( R - Q'*A ) / ( M * norm(A) * EPS )
  • RESULT(2) = norm( I - Q'*Q ) / ( M * EPS )

🫶 Author 🫶

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

Definition at line 124 of file dqrt01p.f.

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🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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mwah 💋 — signed off from LAPACK Version 3.12.0 and /home/abui.../dqrt01p.f(3). 🫶