SLARTV(3)

💅 SLARTV(3) — a girl's guide to a vector of plane rotations ✨

okay so this page lives in the Library Functions Manual, and full transparency bestie, the file is literally /home/abui...RC/slartv.f(3). That's the whole path situation. She's a Fortran file from LAPACK, she's iconic, let's get into it 🎀

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✨ NAME ✨

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

like yes that's the actual NAME section, she's just her whole address, no cap 💀 that's the whole name. moving on.

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🦋 SYNOPSIS 🦋

Functions/Subroutines

subroutine SLARTV (n, x, incx, y, incy, c, s, incc)

SLARTV applies a vector of plane rotations with real cosines and real sines to the elements of a pair of vectors. so literally, it takes your vector, twists it, and hands it back. it's giving ✨ transformation era ✨

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👑 Function/Subroutine Documentation 👑

subroutine SLARTV (integer n, real, dimension( * ) x, integer incx, real,
    dimension( * ) y, integer incy, real, dimension( * ) c, real, dimension(
    * ) s, integer incc)

SLARTV applies a vector of plane rotations with real cosines and real sines to the elements of a pair of vectors. same energy as the synopsis, she's just restating her whole deal because she knows you weren't listening the first time 🫶

🌸 Purpose 🌸

!>
!> SLARTV applies a vector of real plane rotations to elements of the
!> real vectors x and y. For i = 1,2,...,n
!>
!>    ( x(i) ) := (  c(i)  s(i) ) ( x(i) )
!>    ( y(i) )    ( -s(i)  c(i) ) ( y(i) )
!>

okay so this is THE moment. for every i = 1,2,...,n, she takes x(i) and y(i) and multiplies them by that little 2x2 rotation matrix with c(i) and s(i) cosines and sines on top and -s(i), c(i) on the bottom. everything's a matrix if you're brave enough 💅 that's literally the whole function. that's her whole job.

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🎀 Parameters 🎀

• N — N is INTEGER. the number of plane rotations to be applied. she's the count, she's the queen, she decides how many times we spin 🔥
• X — X is REAL array, dimension (1+(N-1)*INCX). the vector x. our first main character ✨
• INCX — INCX is INTEGER. the increment between elements of X. INCX > 0. like, the stride between her elements, and she's gotta be positive, no exceptions bestie 🌈
• Y — Y is REAL array, dimension (1+(N-1)*INCY). the vector y. our second main character, she's the costar 🦋
• INCY — INCY is INTEGER. the increment between elements of Y. INCY > 0. same deal as INCX, but for Y. also gotta be positive, we don't do zero or negative strides around here 🍓
• C — C is REAL array, dimension (1+(N-1)*INCC). the cosines of the plane rotations. the c in the matrix, she's the vibe provider 💖
• S — S is REAL array, dimension (1+(N-1)*INCC). the sines of the plane rotations. the s, she's the chaotic one, she gets the negative sign on her second appearance and she eats every time 💅
• INCC — INCC is INTEGER. the increment between elements of C and S. INCC > 0. yes, ONE increment for BOTH of them, they share, it's very cute, and it's gotta be positive too 🙈

⚠️ heads up bestie: INCX > 0, INCY > 0, and INCC > 0 are the stated conditions. don't come at her with negative strides, that's not the assignment ✨

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🧚 Author 🧚

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

four institutions, one icon, the group project actually went well for once 😭

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⭐ Definition at line 107 of file slartv.f. ⭐

line 107, file slartv.f, that's exactly where she lives. screenshot it 💖

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💜 Author 💜

Generated automatically by Doxygen for LAPACK from the source code. so yes she was born from a code generator, she's a nepo baby but she's talented so we let it slide 👑

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that's the whole page, no skips, no cuts 🫶

signing off: this is LAPACK, Version 3.12.0, filed under /home/abui...RC/slartv.f(3), and that's the whole footer bestie — the version and the date/path vibe, all wrapped up. go rotate something 🌸