/home/abui...RC/dlarz.f(3)

🦋 dlarz.f(3) — Library Functions Manual 🦋

okay bestie, welcome to the dlarz.f(3) page in the Library Functions Manual. This is the DLARZ routine, and she is here to apply an elementary reflector. Let's get into it. 💅

---

✨ NAME ✨

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

---

🎀 SYNOPSIS 🎀

🌸 Functions/Subroutines 🌸

subroutine DLARZ (side, m, n, l, v, incv, tau, c, ldc, work)

DLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix. slay. ✨

---

💖 Function/Subroutine Documentation 💖

subroutine DLARZ (character side, integer m, integer n, integer l, double
    precision, dimension( * ) v, integer incv, double precision tau, double
    precision, dimension( ldc, * ) c, integer ldc, double precision,
    dimension( * ) work)

DLARZ applies an elementary reflector (as returned by stzrzf) to a general matrix. iconic behavior, no notes. 👑

🌈 Purpose 🌈

the actual purpose block is giving:

!>
!> DLARZ applies a real elementary reflector H to a real M-by-N
!> matrix C, from either the left or the right. H is represented in the
!> form
!>
!>       H = I - tau * v * v**T
!>
!> where tau is a real scalar and v is a real vector.
!>
!> If tau = 0, then H is taken to be the unit matrix.
!>
!>
!> H is a product of k elementary reflectors as returned by DTZRZF.
!>

💜 Parameters 💜

• SIDE — SIDE is CHARACTER*1. and babes, it picks the side: = 'L': form H * C or = 'R': form C * H. pick your fighter. 💅
• M — M is INTEGER. it's the number of rows of the matrix C.
• N — N is INTEGER. it's the number of columns of the matrix C.
• L — L is INTEGER. the number of entries of the vector V containing the meaningful part of the Householder vectors. If SIDE = 'L', then M >= L >= 0; if SIDE = 'R', then N >= L >= 0.
• V — V is DOUBLE PRECISION array, dimension (1+(L-1)*abs(INCV)). the vector v in the representation of H as returned by DTZRZF. V is not used if TAU = 0.
• INCV — INCV is INTEGER. the increment between elements of v. INCV <> 0. periodt. 🫶
• TAU — TAU is DOUBLE PRECISION. the value tau in the representation of H.
• C — C is DOUBLE PRECISION 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'. she gets a makeover. 💖
• LDC — LDC is INTEGER. the leading dimension of the array C. LDC >= max(1,M).
• WORK — WORK is DOUBLE PRECISION array, dimension (N) if SIDE = 'L' or (M) if SIDE = 'R'.

👑 Author 👑

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

🌟 Contributors: 🌟

A. Petitet, Computer Science Dept., Univ. of Tenn., Knoxville, USA

⭐ Further Details: ⭐

there is no extra tea here — this block is literally just:

!>

Definition at line 144 of file dlarz.f.

---

💅 Author 💅

Generated automatically by Doxygen for LAPACK from the source code.

---

💖 cute sign-off: this page is from LAPACK Version 3.12.0, and the footer path is /home/abui...RC/dlarz.f(3). mwah, bestie. 🎀✨