BLAS/SRC/izamax.f(3)

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version 3.12.0 · 7 versions
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💖 BLAS/SRC/izamax.f 💖

okay bestie, welcome to the LAPACK manual, section 3, and today's main character is BLAS/SRC/izamax.f — the little BLAS routine that finds the biggest vibe in a complex vector. no cap. 🦋

✨ SYNOPSIS ✨

Functions/Subroutines

integer function izamax (n, zx, incx)

IZAMAX 💅

🌸 Function/Subroutine Documentation 🌸

integer function izamax (integer n, complex*16, dimension(*) zx, integer
    incx)

IZAMAX ✨

🎯 Purpose

IZAMAX finds the index of the first element having maximum |Re(.)| + |Im(.)| 👑

translation: it goes through your complex vector, adds the absolute value of each element's real part to the absolute value of its imaginary part, and tells you where the biggest of those sums lives. first one wins if there's a tie — no fight, no tiebreaker, the earliest index takes it. periodt. 💖

🧚 Parameters

  • N — N is INTEGER, and it's literally just the number of elements in your input vector(s). that's it. that's the whole job. 🙈
  • ZX — ZX is a COMPLEX*16 array, dimension ( 1 + ( N - 1 )*abs( INCX ) ). it's the actual vector we're vibing through ✨
  • INCX — INCX is INTEGER, and it's the storage spacing between elements of ZX. iykyk — it's the stride, bestie, the steps you take between one element and the next 💅

👑 Author

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

📜 Further Details:

jack dongarra, 1/15/85.
modified 3/93 to return if incx .le. 0.
modified 12/3/93, array(1) declarations changed to array(*)

the lore!! jack dongarra dropped this on 1/15/85, then in 3/93 it got tweaked so it bails out and returns if incx .le. 0 (yes, if your stride is zero or negative, it's giving nothing, it just returns), and then on 12/3/93 the array(1) declarations got changed to array(*). iconic history right there 🫶

📍 Definition at line 70 of file izamax.f.

🌈 Author

Generated automatically by Doxygen for LAPACK from the source code. (not me writing my own bio, the robots did it 😭)

and that's the whole page, bestie — every flag, every param, every dusty historical note, all intact, nothing skipped, we ate and left no crumbs 💅✨

this was LAPACK Version 3.12.0, dated Tue Nov 28 2023 12:08:41, from BLAS/SRC/izamax.f(3) — mwah, take care of her 🎀💖🦋🌸

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