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

💖 NAME 💖

Okay bestie, this page is from the Library Functions Manual — it’s the slarz.f page for SLARZ, and it’s giving “reflector glow-up” energy. 🎀

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

✨ SYNOPSIS ✨

Functions/Subroutines 🎀

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

SLARZ applies an elementary reflector — the kind stzrzf returns — to a general matrix. 💅

📚 Function/Subroutine Documentation 📚

🫶 subroutine SLARZ 🫶

subroutine SLARZ (character side, integer m, integer n, integer l, real,
    dimension( * ) v, integer incv, real tau, real, dimension( ldc, * ) c,
    integer ldc, real, dimension( * ) work)

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

🎯 Purpose 🎯

Okay so SLARZ 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. No cap.

H is a product of k elementary reflectors as returned by STZRZF. Periodt. 👑

🧸 Parameters 🧸

• SIDE — CHARACTER*1. This one says which side the reflector comes from:
  • = 'L': form H * C
  • = 'R': form C * H
• M — INTEGER. The number of rows of the matrix C.
• N — INTEGER. The number of columns of the matrix C.
• L — INTEGER. The number of entries of the vector V containing the meaningful part of the Householder vectors. If SIDE = 'L', M >= L >= 0; if SIDE = 'R', N >= L >= 0.
• V — REAL array, dimension (1+(L-1)*abs(INCV)). The vector v in the representation of H as returned by STZRZF. V is not used if TAU = 0.
• INCV — INTEGER. The increment between elements of v. INCV <> 0.
• TAU — REAL. The value tau in the representation of H.
• C — REAL 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 — INTEGER. The leading dimension of the array C. LDC >= max(1,M).
• WORK — REAL 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: 🔍

The source page literally just shows !> here. That’s the whole “further details” moment, bestie. 🙈

Definition at line 144 of file slarz.f.

👑 Author 👑

Generated automatically by Doxygen for LAPACK from the source code. 🫶

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Bye bestie 💖 — footer check: this is LAPACK, Version 3.12.0, page /home/abui...RC/slarz.f(3). There’s no date printed in the footer, so I’m not inventing one, fr fr. 🌈