TESTING/EIG/slarfy.f(3)

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version 3.12.1 · 4 versions
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💅 TESTING/EIG/slarfy.f(3) 💅

okay so bestie, this page comes from the Library Functions Manual, and it's the whole vibe check for TESTING/EIG/slarfy.f. The main character is the slarfy subroutine, and she is lowkey iconic. ✨

🌸 NAME 🌸

TESTING/EIG/slarfy.f — the manual page for the slarfy subroutine, periodt.

🎀 SYNOPSIS 🎀

✨ Functions/Subroutines ✨

  • subroutine slarfy (uplo, n, v, incv, tau, c, ldc, work) — the SLARFY moment. 👑

🫶 Function/Subroutine Documentation 🫶

Here's the full signature, exact, no edits:

   subroutine slarfy (character uplo, integer n, real, dimension( * ) v,
       integer incv, real tau, real, dimension( ldc, * ) c, integer ldc, real,
       dimension( * ) work)

SLARFY

🌈 Purpose:

okay so SLARFY applies an elementary reflector, or Householder matrix, H, to an n x n symmetric matrix C, from both the left and the right. Obsessed with a two-sided moment. 💅

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. fr fr, that's the whole purpose.

💖 Parameters 💖

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

👑 Author 👑

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

📍 Definition at line 📍

Definition at line 107 of file slarfy.f.

🌸 Author 🌸

Generated automatically by Doxygen for LAPACK from the source code.

okay bestie, that's a wrap 💖 The footer/source stamp is LAPACK Version 3.12.0, and the page is TESTING/EIG/slarfy.f(3) — that's the version/page info this copy shows, and no cap, that's the whole source/version/date situation. 🎀

📦 where this page comes from