SRC/sorglq.f(3)

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version 3.12.1 · 7 versions
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💅 SRC/sorglq.f 💅

From the LAPACK Library Functions Manual, bestie — this is the source page for SRC/sorglq.f. Strap in, it's giving linear algebra but make it cute. 🎀

🎀 NAME 🎀

SRC/sorglq.f — that's the name, and yes, she's iconic. ✨

✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

       subroutine sorglq (m, n, k, a, lda, tau, work, lwork, info)
           SORGLQ

🦋 Function/Subroutine Documentation 🦋

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

🌈 Purpose 🌈

Okay so picture this: SORGLQ generates an M-by-N real matrix Q with orthonormal rows. It's defined as the first M rows of a product of K elementary reflectors of order N — like this iconic little chain:

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

And it's all as returned by SGELQF. Periodt. 💅

🎀 Parameters 🎀

  • M — INTEGER. The number of rows of the matrix Q. M >= 0. 💖
  • N — INTEGER. The number of columns of the matrix Q. N >= M. 🦋
  • K — INTEGER. The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. ✨
  • A — REAL array, dimension (LDA,N). On entry, the i-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGELQF in the first k rows of its array argument A. On exit, the M-by-N matrix Q. 👑
  • LDA — INTEGER. The first dimension of the array A. 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 SGELQF. 💜
  • WORK — REAL array, dimension (MAX(1,LWORK)). On exit, if INFO = 0, WORK(1) returns the optimal LWORK. 🫶
  • LWORK — INTEGER. The dimension of the array WORK. LWORK >= max(1,M). For optimum performance LWORK >= M*NB, where NB is the optimal blocksize. 🔥 If LWORK = -1, then a workspace query is assumed; the routine only calculates the optimal size of the WORK array, returns this value as the first entry of the WORK array, and no error message related to LWORK is issued by XERBLA. 💀
  • INFO — 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 📌

Definition at line 126 of file sorglq.f. 🎀

💖 Author 💖

Generated automatically by Doxygen for LAPACK from the source code. No cap. ✨

LAPACK, Version 3.12.0, from SRC/sorglq.f(3) — that's the footer vibe, bestie, and we are out. 💅💖🎀

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