BLAS/SRC/dscal.f(3)

📦
version 3.12.0 · 7 versions
, in centos-stream 10, fedora 43, fedora 44

💖 BLAS/SRC/dscal.f — the LAPACK manual, bestie edition 💖

okay so you opened the manual for BLAS/SRC/dscal.f and honestly? slay. it's a LAPACK girlie, it lives in the BLAS/SRC folder, and it is here to do exactly one thing extremely well. let's get into it 🎀

✨ NAME ✨

BLAS/SRC/dscal.f — that's the file, that's the name, no notes 💅

🌸 SYNOPSIS 🌸

Functions/Subroutines

  • subroutine dscal (n, da, dx, incx) — this is DSCAL, the main character 👑

🦋 Function/Subroutine Documentation 🦋

subroutine dscal (integer n, double precision da, double precision,
    dimension(*) dx, integer incx)

DSCAL — say it with me, bestie. it's giving legend behaviour.

🎯 Purpose:

DSCAL scales a vector by a constant. uses unrolled loops for increment equal to 1.

so like, it takes your vector and multiplies everything by a constant. and when INCX equals 1? it whips out the unrolled loops, which is lowkey the fast path. iconic optimization moment fr fr ✨

🌈 Parameters

  • N — N is INTEGER. it's the number of elements in your input vector(s). simple as that, no cap.
  • DA — DA is DOUBLE PRECISION. On entry, DA specifies the scalar alpha. this is your constant, your multiplier, your moment 💫
  • DX — DX is DOUBLE PRECISION array, dimension ( 1 + ( N - 1 )*abs( INCX ) ). yeah it's a whole formula for the size, just trust the process 🫶
  • INCX — INCX is INTEGER. it's the storage spacing between elements of DX. think of it as the stride, the lil hop between each element 🐇

👑 Author

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

the whole squad came together for this one, we love a collab 💜

📜 Further Details:

jack dongarra, linpack, 3/11/78.
modified 3/93 to return if incx .le. 0.
modified 12/3/93, array(1) declarations changed to array(*)

the lore is real — jack dongarra, linpack, 3/11/78. then in 3/93 it got modified to return if incx .le. 0, and then 12/3/93 the array(1) declarations got changed to array(*). character development fr 😭

📍 Definition

Definition at line 78 of file dscal.f.

🎀 Author 🎀

Generated automatically by Doxygen for LAPACK from the source code. (yes bestie, a robot wrote the docs, and it ate 💅)

and that's the whole page!! Version 3.12.0, dated Tue Nov 28 2023 12:08:41 — mwah, go scale some vectors, you've got this 🌟💖

📦 where this page comes from