larfy(3)

📦
version 3.12.1 · 9 versions
, in arch rolling

🦋 larfy(3) 🦋

okay so this page is from the Library Functions Manual, and it's giving "tiny LAPACK family, huge Householder reflector energy" 💅✨.

🌸 NAME 🌸

larfy — larfy: apply Householder reflector symmetrically (2-sided)

✨ SYNOPSIS ✨

🎀 Functions 🎀

  • subroutine clarfy (uplo, n, v, incv, tau, c, ldc, work) — CLARFY
  • subroutine dlarfy (uplo, n, v, incv, tau, c, ldc, work) — DLARFY
  • subroutine slarfy (uplo, n, v, incv, tau, c, ldc, work) — SLARFY
  • subroutine zlarfy (uplo, n, v, incv, tau, c, ldc, work) — ZLARFY

🫶 Detailed Description 🫶

so this heading is literally here, and the detailed description section is just... the heading bestie 💀✨ iconic minimalism, no notes.

💖 Function Documentation 💖

🌈 clarfy — CLARFY

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

✨ Purpose ✨

CLARFY applies an elementary reflector, or Householder matrix, H, to an n x n Hermitian matrix C, from both the left and the right.

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.

🎀 Parameters 🎀

  • UPLO — UPLO is CHARACTER*1. 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 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. The value tau as described above.
  • C — C is COMPLEX 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 array, dimension (N).

👑 Author 👑

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file clarfy.f.

🦋 dlarfy — DLARFY

subroutine dlarfy (character uplo, integer n, double precision, dimension( *
    ) v, integer incv, double precision tau, double precision, dimension(
    ldc, * ) c, integer ldc, double precision, dimension( * ) work)

✨ Purpose ✨

DLARFY applies an elementary reflector, or Householder matrix, H, to an n x n symmetric matrix C, from both the left and the right.

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.

🎀 Parameters 🎀

  • UPLO — UPLO is CHARACTER*1. Specifies whether the upper or lower triangular part of the symmetric 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 DOUBLE PRECISION 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 DOUBLE PRECISION. The value tau as described above.
  • C — C is DOUBLE PRECISION 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 DOUBLE PRECISION array, dimension (N).

👑 Author 👑

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file dlarfy.f.

🍓 slarfy — SLARFY

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

✨ Purpose ✨

SLARFY applies an elementary reflector, or Householder matrix, H, to an n x n symmetric matrix C, from both the left and the right.

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.

🎀 Parameters 🎀

  • UPLO — UPLO is CHARACTER*1. Specifies whether the upper or lower triangular part of the symmetric 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 REAL 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 REAL. The value tau as described above.
  • C — C is REAL 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 REAL array, dimension (N).

👑 Author 👑

Univ. of Tennessee

Univ. of California Berkeley

Univ. of Colorado Denver

NAG Ltd.

Definition at line 107 of file slarfy.f.

🧚 zlarfy — ZLARFY

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)

✨ Purpose ✨

ZLARFY applies an elementary reflector, or Householder matrix, H, to an n x n Hermitian matrix C, from both the left and the right.

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.

🎀 Parameters 🎀

  • UPLO — UPLO is CHARACTER*1. 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 👑

Generated automatically by Doxygen for LAPACK from the source code.

and that's the sign-off bestie 🫶💖: the footer energy is LAPACK, Version 3.12.0, larfy(3) — no separate date line, just that final cute little stamp, periodt 💅✨

📦 where this page comes from