TESTING/LIN/sqrt01p.f(3)

💖 TESTING/LIN/sqrt01p.f 💖

okay bestie, welcome to the LAPACK Library Functions Manual page for TESTING/LIN/sqrt01p.f — she's a QR-factorization test routine and she came to serve. ✨

💅 NAME

TESTING/LIN/sqrt01p.f

That's it. That's the name. Short, iconic, done. 🎀

👑 SYNOPSIS

Functions/Subroutines

subroutine sqrt01p (m, n, a, af, q, r, lda, tau, work, lwork, rwork,
    result)
    SQRT01P

🧚 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

So SQRT01P is the test bestie for SGEQRFP, which computes the QR factorization of an m-by-n matrix A. It also partially tests SORGQR, which forms the m-by-m orthogonal matrix Q. 💅

SQRT01P compares R with Q'*A, and checks that Q is orthogonal. No cap, that's literally the whole assignment. 🦋

📋 Parameters

M

M is INTEGER and it's the number of rows of the matrix A. M >= 0. 🫶

N

N is INTEGER and it's the number of columns of the matrix A. N >= 0. 🌸

A

A is a REAL array, dimension (LDA,N). It's the m-by-n matrix A. 💖

AF

AF is a REAL array, dimension (LDA,N). It holds details of the QR factorization of A, as returned by SGEQRFP. For further details, see SGEQRFP. ✨

Q

Q is a REAL array, dimension (LDA,M). It's the m-by-m orthogonal matrix Q. 👑

R

R is a REAL array, dimension (LDA,max(M,N)). ⭐

LDA

LDA is INTEGER and it's the leading dimension of the arrays A, AF, Q and R. It must satisfy LDA >= max(M,N). 🫡

TAU

TAU is a REAL array, dimension (min(M,N)). These are the scalar factors of the elementary reflectors, as returned by SGEQRFP. 🧚

WORK

WORK is a REAL array, dimension (LWORK). 🍓

LWORK

LWORK is INTEGER and it's the dimension of the array WORK. 💜

RWORK

RWORK is a REAL array, dimension (M). 🌈

RESULT

RESULT is a REAL array, dimension (2). It carries 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

Definition at line 124 of file sqrt01p.f.

🫶 Author

Generated automatically by Doxygen for LAPACK from the source code.

---

kiss kiss 💋 — this footer is giving LAPACK Version 3.12.0 and page TESTING/LIN/sqrt01p.f(3). Date? Not printed on this footer, bestie, so I'm not inventing one. 🫶