TESTING/EIG/zlarfy.f(3)

🎀 TESTING/EIG/zlarfy.f(3) 🎀

okay bestie, welcome to the Library Functions Manual glow-up for TESTING/EIG/zlarfy.f. It’s giving tiny-but-iconic LAPACK subroutine energy, and we’re gonna understand it fr fr.

---

✨ SYNOPSIS ✨

💖 Functions/Subroutines 💖

• subroutine zlarfy (uplo, n, v, incv, tau, c, ldc, work) — ZLARFY

🦋 Function/Subroutine Documentation 🦋

subroutine zlarfy (character uplo, integer n, complex*16, dimension( * ) v,
    integer incv, complex*16 tau, complex*16, dimension( ldc, * ) c, integer
    ldc, complex*16, dimension( * ) work)

ZLARFY — the main character, no cap.

🌸 Purpose 🌸

So ZLARFY applies an elementary reflector, or Householder matrix, H, to an n x n Hermitian matrix C, from both the left and the right. Both sides, because balance 💅

H is represented in the form:

H = I - tau * v * v'

where tau is a scalar and v is a vector.

If tau is zero, then H is taken to be the unit matrix. Important vibe check 🫶

💅 Parameters 💅

• UPLO — UPLO is CHARACTER*1. It specifies whether the upper or lower triangular part of the Hermitian matrix C is stored.
  • = 'U': Upper triangle
  • = 'L': Lower triangle
• N — N is INTEGER. The number of rows and columns of the matrix C. N >= 0.
• V — V is COMPLEX*16 array, dimension (1 + (N-1)*abs(INCV)). The vector v as described above.
• INCV — INCV is INTEGER. The increment between successive elements of v. INCV must not be zero.
• TAU — TAU is COMPLEX*16. The value tau as described above.
• C — C is COMPLEX*16 array, dimension (LDC, N). On entry, the matrix C. On exit, C is overwritten by H * C * H'.
• LDC — LDC is INTEGER. The leading dimension of the array C. LDC >= max( 1, N ).
• WORK — WORK is COMPLEX*16 array, dimension (N).

👑 Author 👑

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

Definition at line 107 of file zlarfy.f.

🤖 Author (auto-generated) 🤖

Generated automatically by Doxygen for LAPACK from the source code.

---

xoxo, your Unix bestie 💖 — final footer check: LAPACK Version 3.12.0 TESTING/EIG/zlarfy.f(3). slay and goodbye! 🎀