TESTING/LIN/dlqt01.f(3)

📦
version 3.12.1 · 3 versions
, in arch rolling

💖 NAME 💖

TESTING/LIN/dlqt01.f — okay so this is the whole page name, bestie, from the LAPACK Library Functions Manual. We're talking about the DLQT01 routine page, and every fact is staying put. ✨

🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine dlqt01 (m, n, a, af, q, l, lda, tau, work, lwork, rwork, result)
    DLQT01
  • DLQT01 — the routine in the synopsis, showing up like the main character. 👑

🌸 Function/Subroutine Documentation 🌸

subroutine dlqt01 (integer m, integer n, double precision, dimension( lda, * ) a, double precision, dimension( lda, * ) af, double precision, dimension( lda, * ) q, double precision, dimension( lda, * ) l, integer lda, double precision, dimension( * ) tau, double precision, dimension( lwork ) work, integer lwork, double precision, dimension( * ) rwork, double precision, dimension( * ) result)
    DLQT01

Full signature check: that's the exact argument list, and DLQT01 is the name. No cap.

🎀 Purpose: 🎀

Okay so DLQT01 tests DGELQF, which computes the LQ factorization of an m-by-n matrix A, and it partially tests DORGLQ which forms the n-by-n orthogonal matrix Q.

DLQT01 compares L with A*Q', and checks that Q is orthogonal. That's the purpose, periodt. 💅

🌈 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 LQ factorization of A, as returned by DGELQF. See DGELQF for further details.
  • Q — Q is DOUBLE PRECISION array, dimension (LDA,N); the n-by-n orthogonal matrix Q.
  • L — L is DOUBLE PRECISION array, dimension (LDA,max(M,N)).
  • LDA — LDA is INTEGER; the leading dimension of the arrays A, AF, Q and L. LDA >= max(M,N).
  • TAU — TAU is DOUBLE PRECISION array, dimension (min(M,N)); the scalar factors of the elementary reflectors, as returned by DGELQF.
  • 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 (max(M,N)).
  • RESULT — RESULT is DOUBLE PRECISION array, dimension (2); the test ratios:
    • RESULT(1) = norm( L - A*Q' ) / ( N * norm(A) * EPS )
    • RESULT(2) = norm( I - Q*Q' ) / ( N * EPS )

👑 Author 👑

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

Definition at line 124 of file dlqt01.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

Cute footer sign-off, bestie: LAPACK Version 3.12.0, page TESTING/LIN/dlqt01.f(3) — that's the footer vibe, and we are so done. 💖💅

📦 where this page comes from