CUNML2(3)

okay bestie, welcome to CUNML2(3) — the LAPACK manual page that's literally named after a Fortran file and absolutely ate. 💅✨

🎀 NAME 🎀

This is the source-file path, no cap:

/home/abuild/rpmbuild/BUILD/lapack-
static-3.12.0-build/lapack-3.12.0/SRC/cunml2.f

yes, the NAME section is a build path. iconic. 🫶

✨ SYNOPSIS ✨

Functions/Subroutines

subroutine CUNML2 (side, trans, m, n, k, a, lda, tau, c, ldc, work, info)

CUNML2 multiplies a general matrix by the unitary matrix from the LQ factorization determined by cgelqf (unblocked algorithm).

💅 Function/Subroutine Documentation 💅

subroutine CUNML2 (character side, character trans, integer m, integer n,
     integer k, complex, dimension( lda, * ) a, integer lda, complex,
     dimension( * ) tau, complex, dimension( ldc, * ) c, integer ldc,
     complex, dimension( * ) work, integer info)

CUNML2 multiplies a general matrix by the unitary matrix from the LQ factorization determined by cgelqf (unblocked algorithm).

🎯 Purpose 🎯

bestie, here's the whole vibe: CUNML2 overwrites the general complex m-by-n matrix C with:

      Q * C  if SIDE = 'L' and TRANS = 'N', or

      Q**H* C  if SIDE = 'L' and TRANS = 'C', or

      C * Q  if SIDE = 'R' and TRANS = 'N', or

      C * Q**H if SIDE = 'R' and TRANS = 'C',

where Q is a complex unitary matrix defined as the product of k elementary reflectors:

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

as returned by CGELQF. Q is of order m if SIDE = 'L' and of order n if SIDE = 'R'. 🦋

🌸 Parameters 🌸

🦋 SIDE 🦋

SIDE is CHARACTER*1.

• = 'L': apply Q or Q**H from the Left
• = 'R': apply Q or Q**H from the Right

🦋 TRANS 🦋

TRANS is CHARACTER*1.

• = 'N': apply Q (No transpose)
• = 'C': apply Q**H (Conjugate transpose)

🦋 M 🦋

M is INTEGER.

The number of rows of the matrix C. M >= 0. 💖

🦋 N 🦋

N is INTEGER.

The number of columns of the matrix C. N >= 0. 💖

🦋 K 🦋

K is INTEGER.

The number of elementary reflectors whose product defines the matrix Q.

If SIDE = 'L', M >= K >= 0; if SIDE = 'R', N >= K >= 0.

🦋 A 🦋

A is COMPLEX array, dimension:

                               (LDA,M) if SIDE = 'L',
                               (LDA,N) if SIDE = 'R'

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.

A is modified by the routine but restored on exit. 🫶

🦋 LDA 🦋

LDA is INTEGER.

The leading dimension of the array A. LDA >= max(1,K). ✨

🦋 TAU 🦋

TAU is COMPLEX array, dimension (K).

TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by CGELQF.

🦋 C 🦋

C is COMPLEX array, dimension (LDC,N).

On entry, the m-by-n matrix C.

On exit, C is overwritten by Q*C or Q**H*C or C*Q**H or C*Q. 🔥

🦋 LDC 🦋

LDC is INTEGER.

The leading dimension of the array C. LDC >= max(1,M). ✨

🦋 WORK 🦋

WORK is COMPLEX array, dimension:

                                   (N) if SIDE = 'L',
                                   (M) if SIDE = 'R'

🦋 INFO 🦋

INFO is INTEGER.

• = 0: successful exit
• < 0: if INFO = -i, the i-th argument had an illegal value

👑 Author 👑

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

Definition at line 157 of file cunml2.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code.

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