CUNGL2(3)

💅 NAME 💅

ok so bestie, this is the manual page for /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cungl2.f — yes that's the whole entire path, she's extra like that, we stan a file system icon ✨ (it's a cungl2.f situation, LAPACK-static-3.12.0-build coded, no notes 🎀)

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✨ SYNOPSIS ✨

🌸 Functions/Subroutines 🌸

• subroutine CUNGL2 (m, n, k, a, lda, tau, work, info) — CUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm). like, that's her whole job and she does it flawlessly 💅

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👑 Function/Subroutine Documentation 👑

subroutine CUNGL2 (integer m, integer n, integer k, complex, dimension( lda, * ) a, integer lda, complex, dimension( * ) tau, complex, dimension( * ) work, integer info)

so CUNGL2 generates all or part of the unitary matrix Q from an LQ factorization determined by cgelqf (unblocked algorithm). that's the vibe check and she PASSED 💖

🦋 Purpose 🦋

ok so listen up bestie, here's the tea, quoted with love:

!>
!> CUNGL2 generates an m-by-n complex matrix Q with orthonormal rows,
!> which is defined as the first m rows of a product of k elementary
!> reflectors of order n
!>
!>       Q  =  H(k)**H . . . H(2)**H H(1)**H
!>
!> as returned by CGELQF.
!>

like, m-by-n, orthonormal rows, the first m rows of that product of k elementary reflectors of order n, exactly as CGELQF handed them to her. no cap, that formula is lowkey iconic 🔥

🧚 Parameters 🧚

• M — M is INTEGER, and it's the number of rows of the matrix Q. the rule is M >= 0 (respect the boundary, she's not negotiable about it) ✨

!>          M is INTEGER
!>          The number of rows of the matrix Q. M >= 0.
!>

• N — N is INTEGER, the number of columns of the matrix Q. and heads up: N >= M. that's the law, bestie 😭

!>          N is INTEGER
!>          The number of columns of the matrix Q. N >= M.
!>

• K — K is INTEGER and it's the number of elementary reflectors whose product defines the matrix Q. constraint: M >= K >= 0. sandwiched between two bounds, main character energy honestly 👑

!>          K is INTEGER
!>          The number of elementary reflectors whose product defines the
!>          matrix Q. M >= K >= 0.
!>

• A — A is a COMPLEX 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 CGELQF in the first k rows of its array argument A. on exit? boom, she's the m by n matrix Q. full glow-up transformation, we love a before-and-after 💅

!>          A is COMPLEX 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 CGELQF in the first 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. requirement: LDA >= max(1,M). don't skimp on the leading dimension, she WILL notice 🫶

!>          LDA is INTEGER
!>          The first dimension of the array A. LDA >= max(1,M).
!>

• TAU — TAU is a COMPLEX array, dimension (K). TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGELQF. she's the little scalar factor that could 💜

!>          TAU is COMPLEX array, dimension (K)
!>          TAU(i) must contain the scalar factor of the elementary
!>          reflector H(i), as returned by CGELQF.
!>

• WORK — WORK is a COMPLEX array, dimension (M). that's it, that's the whole description, she's a workspace and she's thriving 🌸

!>          WORK is COMPLEX array, dimension (M)
!>

• INFO — INFO is INTEGER, the exit report card:
  • = 0: successful exit 🎉 slay
  • < 0: if INFO = -i, the i-th argument has an illegal value 💀 someone put a bad value in, not her fault fr fr

!>          INFO is INTEGER
!>          = 0: successful exit
!>          < 0: if INFO = -i, the i-th argument has an illegal value
!>

⭐ Author ⭐

the legends behind the code, in their natural habitat:

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

🌈 Definition at line 112 of file cungl2.f. 🌈

yes bestie, line 112, that's exactly where it lives, go look, she's right there 🦋

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💀 Author 💀

Generated automatically by Doxygen for LAPACK from the source code. like, a robot made this heading, not me, i'm just the messenger 🙈

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ok and that's the whole page!! everything above is LAPACK Version 3.12.0, dated /home/abui...RC/cungl2.f(3), from the source at /home/abuild/rpmbuild/BUILD/lapack-static-3.12.0-build/lapack-3.12.0/SRC/cungl2.f — mwah, go call her with the right LDA, ily, bye 🫶💖🎀