SRC/sorgr2.f(3)

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version 3.12.1 · 7 versions
, in arch rolling

💖 SRC/sorgr2.f(3) 💖

okay bestie, welcome to the Library Functions Manual entry for SRC/sorgr2.f(3) — this is the LAPACK page for sorgr2, and it's giving "unblocked RQ factorization but make it orthogonal." No cap, we're gonna walk through every parameter and constraint. 🫶

🌸 NAME 🌸

SRC/sorgr2.f — that's the file name, and the function inside is sorgr2. Short name section, iconic behavior. 💅

✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

  • subroutine sorgr2 (m, n, k, a, lda, tau, work, info) — SORGR2 generates all or part of the orthogonal matrix Q from an RQ factorization determined by sgerqf (unblocked algorithm).

🦋 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). 💖

🎯 Purpose 🎯

SORGR2 generates an m by n real matrix Q with orthonormal rows, which 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. ✨

🌈 Parameters 🌈

  • M — M is INTEGER. The number of rows of the matrix Q. Constraint: M >= 0. 💜
  • N — N is INTEGER. The number of columns of the matrix Q. Constraint: N >= M. 🦋
  • K — K is INTEGER. The number of elementary reflectors whose product defines the matrix Q. Constraint: M >= K >= 0. 🌟
  • A — A is REAL array, dimension (LDA,N). On entry, the (m-k+i)-th row must contain the vector which 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, the m by n matrix Q. 🫶
  • LDA — LDA is INTEGER. The first dimension of the array A. Constraint: LDA >= max(1,M). 💅
  • TAU — TAU is REAL array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by SGERQF. 🎀
  • WORK — WORK is REAL array, dimension (M). 🍓
  • INFO — INFO is INTEGER. = 0: successful exit. < 0: if INFO = -i, the i-th argument has an illegal value. 💀

💖 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.

byeee bestie, official sign-off: LAPACK Version 3.12.0, source SRC/sorgr2.f(3) 💋✨🦋

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