SRC/clarf1l.f(3)

💖 NAME 💖

okay so bestie, this page is from the Library Functions Manual, and it's all about SRC/clarf1l.f — literally the file, no cap. That's the name. Periodt. 🫶

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

• subroutine clarf1l (side, m, n, v, incv, tau, c, ldc, work) — the group-chat summary is: CLARF1L applies an elementary reflector to a general rectangular.

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🦋 Function/Subroutine Documentation 🦋

subroutine clarf1l (character side, integer m, integer n, complex,
       dimension( * ) v, integer incv, complex tau, complex, dimension( ldc, *
       ) c, integer ldc, complex, dimension( * ) work)

CLARF1L applies an elementary reflector to a general rectangular — that's the tagline, iykyk. 💅

🌸 Purpose 🌸

okay so here's the vibe: CLARF1L applies a complex elementary reflector H to a complex m by n matrix C, from either the left or the right. H is represented in the form:

H = I - tau * v * v**H

where tau is a real scalar and v is a real vector assuming v(lastv) = 1, where lastv is the last non-zero element. 🌈

If tau = 0, then H is taken to be the unit matrix. Simple as that.

To apply H**H (the conjugate transpose of H), supply conjg(tau) instead of tau. 🔥

💅 Parameters 💅

SIDE

Type: CHARACTER*1. It picks the side, bestie:

• = 'L': form H * C
• = 'R': form C * H

M

Type: INTEGER. The number of rows of the matrix C. 📏

N

Type: INTEGER. The number of columns of the matrix C. 📐

V

Type: COMPLEX array, dimension:

           (1 + (M-1)*abs(INCV)) if SIDE = 'L'
        or (1 + (N-1)*abs(INCV)) if SIDE = 'R'

This is the vector v in the representation of H. V is not used if TAU = 0. 🫶

INCV

Type: INTEGER. The increment between elements of v. INCV > 0. ⭐

TAU

Type: COMPLEX. The value tau in the representation of H. 🎀

C

Type: COMPLEX array, dimension (LDC,N).

On entry, the m by n matrix C. On exit, C is overwritten by the matrix H * C if SIDE = 'L', or C * H if SIDE = 'R'. 💖

LDC

Type: INTEGER. The leading dimension of the array C. LDC >= max(1,M). 🦋

WORK

Type: COMPLEX array, dimension:

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

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👑 Author 👑

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

Definition at line 128 of file clarf1l.f. 🌟

🌈 Author 🌈

Generated automatically by Doxygen for LAPACK from the source code.

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k bye bestie — this iconic page is LAPACK Version 3.12.0, SRC/clarf1l.f(3). Stay slay, and don't forget conjg(tau) when you need H**H 💅✨