SRC/dlarfgp.f(3)

🌸 SRC/dlarfgp.f 🌸

okay bestie, welcome to the Library Functions Manual entry for SRC/dlarfgp.f — yes that's the whole name section, it's literally just the file path, iconic minimalism honestly 💅

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✨ SYNOPSIS ✨

🎀 Functions/Subroutines 🎀

subroutine dlarfgp (n, alpha, x, incx, tau)

DLARFGP generates an elementary reflector (Householder matrix) with non-negative beta. that's the whole vibe, no cap 🦋

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👑 Function/Subroutine Documentation 👑

subroutine dlarfgp (integer n, double precision alpha, double precision, dimension( * ) x, integer incx, double precision tau)

DLARFGP generates an elementary reflector (Householder matrix) with non-negative beta — she's giving orthogonal transformation energy and we're obsessed 🫶

💜 Purpose

so here's the tea, bestie — DLARFGP generates a real elementary reflector H of order n, such that

      H * ( alpha ) = ( beta ),   H**T * H = I.
          (   x   )   (   0  )

where alpha and beta are scalars, beta is non-negative, and x is an (n-1)-element real vector. H is represented in the form

      H = I - tau * ( 1 ) * ( 1 v**T ) ,
                    ( v )

where tau is a real scalar and v is a real (n-1)-element vector. main character decomposition fr fr 🔥

and listen — if the elements of x are all zero, then tau = 0 and H is taken to be the unit matrix. literally the "nothing to see here" case and honestly? respect 🙈

🌈 Parameters

• N — N is INTEGER, the order of the elementary reflector. it's the size of the whole situation ✨
• ALPHA — ALPHA is DOUBLE PRECISION. on entry, the value alpha. on exit, it is overwritten with the value beta. so she gets a whole glow-up mid-call, love that for her 💅
• X — X is DOUBLE PRECISION array, dimension (1+(N-2)*abs(INCX)). on entry, the vector x. on exit, it is overwritten with the vector v. same deal, full transformation arc 🦋
• INCX — INCX is INTEGER, the increment between elements of X. INCX > 0. non-negotiable, positive only, read the room bestie 😭
• TAU — TAU is DOUBLE PRECISION, the value tau. short name, big responsibilities 👑

🧚 Author

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

Definition at line 103 of file dlarfgp.f. yes she's at line 103, go say hi 🌸

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💖 Author

Generated automatically by Doxygen for LAPACK from the source code. not a human, just vibes and automation, slay ⭐

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ok that's the whole page bestie — every parameter, every formula, every author line, all accounted for. no notes. 🎀

LAPACK · Version 3.12.0 · SRC/dlarfgp.f(3) — mwah, bye, drink some water 💜🦋💅