lis_array_matvect(3)

✨ lis_array_matvect — it's giving matrix-vector product ✨

okay bestie, so this is a Lis Library Function and it lives in the lis_array_matvect(3) page, section 3, and honestly? it's a lil workhorse. 💅

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🌸 SYNOPSIS 🌸

#include "lis.h"

LIS_INT lis_array_matvect(LIS_INT n, LIS_SCALAR a[], LIS_SCALAR x[],
LIS_SCALAR y[], LIS_INT op);

like, that's the whole signature, no notes. 🫶

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💖 DESCRIPTION 💖

Calculate the matrix-vector product A^Tx.

no cap, that's literally the whole job. she takes your matrix, she takes your vector, she does the lil transpose-multiply thing. main character energy tbh. 👑

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🎀 INPUT 🎀

• n — the size of the matrix and vectors. she needs to know how big everything is, okay? she's not a mind reader. 🙈
• a — the array that stores matrix A of size n * n. yes that's n squared, she's thicc like that. 💀
• x — the array that stores vector x of size n.
• y — the array that stores vector y of size n.
• op — the vibe check, aka which mode we're in:
  • LIS_INS_VALUE — y = A^Tx (fresh y, insert the value, slay ✨)
  • LIS_SUB_VALUE — y = y - A^Tx (subtract the product from the y you already had, subtraction girlies rise 🌈)

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🦋 OUTPUT 🦋

• y — y. yeah. it's y. she returns y and y is where the answer lives. periodt. 💜

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⭐ EXIT STATUS ⭐

the following exit values are returned:

• 0 — the process is normally terminated. she ate and left no crumbs. 👑
• unspecified — an error occurred. not iconic. something went wrong and we do not know what. 😭

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🌈 SEE ALSO 🌈

• lis(3)
• http://www.ssisc.org/lis/

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okay that's the whole page bestie, you're so welcome 💖

this was the Lis Library Functions manual page lis_array_matvect(3), dated 3 Dec 2014 — shoutout to the source and version, they came through fr fr. go forth and multiply (matrices). 🧚🌸