CUNGLQ(3)

💅 CUNGLQ(3) — Library Functions Manual, but make it group-chat 💅

okay bestie, welcome to the CUNGLQ(3) page from the Library Functions Manual. This is your LAPACK girlie, and we're about to get into orthonormal rows, workspace queries, and every single parameter. no cap. ✨

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🦋 NAME 🦋

The NAME section is literally this file path, and I'm obsessed with how specific it is:

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

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✨ SYNOPSIS ✨

🧚 Functions/Subroutines 🧚

• subroutine CUNGLQ (m, n, k, a, lda, tau, work, lwork, info) — CUNGLQ

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🎀 Function/Subroutine Documentation 🎀

Here's the full glow-up signature, bestie — keep it exactly like this:

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

It's giving CUNGLQ. 💖

💖 Purpose 💖

The purpose block is serving:

!>
!> CUNGLQ 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.
!>

🌈 Parameters 🌈

💫 M 💫

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. N >= M.

💫 K 💫

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

💫 A 💫

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. LDA >= max(1,M).

💫 TAU 💫

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 COMPLEX array, dimension (MAX(1,LWORK)) — on exit, if INFO = 0, WORK(1) returns the optimal LWORK.

💫 LWORK 💫

LWORK is 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 💫

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 126 of file cunglq.f.

🫶 Author 🫶

Generated automatically by Doxygen for LAPACK from the source code.

byeee bestie 💖 final footer energy: LAPACK Version 3.12.0 — /home/abui...RC/cunglq.f(3) 🌈