SORGR2(3)

SORGR2(3) 💅

Okay bestie, welcome to SORGR2(3) — yep, straight out of the Library Functions Manual, and it is a LAPACK page. This whole thing is about one source file, and yes, it is giving absolute-path main character energy.

💖 NAME

The source file for this entire page is:

/home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/sorgr2.f

✨ SYNOPSIS

Functions/Subroutines

subroutine SORGR2 (m, n, k, a, lda, tau, work, info)

This one does the thing: SORGR2 generates all or part of the orthogonal matrix Q from an RQ factorization determined by sgerqf (unblocked algorithm). No cap.

🦋 Function/Subroutine Documentation 🦋

subroutine SORGR2 (integer m, integer n, integer k, real, dimension( lda, *
) a, integer lda, real, dimension( * ) tau, real, dimension( * ) work,
integer info)

SORGR2 generates all or part of the orthogonal matrix Q from an RQ factorization determined by sgerqf (unblocked algorithm). Same flex, now with the full signature.

Purpose

SORGR2 generates an m by n real matrix Q with orthonormal rows. Q is defined as the last m rows of a product of k elementary reflectors of order n:

Q  =  H(1) H(2) . . . H(k)

...as returned by SGERQF. That is the whole plot. 💫

Parameters

• M — INTEGER. Number of rows of matrix Q. Must satisfy M >= 0.
• N — INTEGER. Number of columns of matrix Q. Must satisfy N >= M.
• K — INTEGER. Number of elementary reflectors whose product defines matrix Q. Must satisfy M >= K >= 0.
• A — REAL array, dimension (LDA,N). On entry, the (m-k+i)-th row must contain the vector that defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGERQF in the last k rows of its array argument A. On exit, A is the m by n matrix Q.
• LDA — INTEGER. First dimension of the array A. Must satisfy LDA >= max(1,M).
• TAU — REAL array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SGERQF.
• WORK — REAL array, dimension (M).
• INFO — INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument has an illegal value.

These bounds are the vibe check, bestie: M >= 0, N >= M, M >= K >= 0, and LDA >= max(1,M) are requirements, not suggestions.

Author

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 113 of file sorgr2.f.

💜 Author

Generated automatically by Doxygen for LAPACK from the source code.

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💖 cute sign-off: the footer vibes are LAPACK, Version 3.12.0, and the source path is /home/abui...RC/sorgr2.f(3) — no separate date line is shown, just that version and source flex. Bye bestie, go slay those reflectors! 🫶✨