lis_array_matvect(3f)

💖 lis_array_matvect — calculate the matrix vector product 💖

okay bestie, welcome to lis_array_matvect(3f) — she's a Fortran subroutine from the Lis Library Functions and she does exactly one thing and does it flawlessly. no cap. 🫶

✨ SYNOPSIS ✨

subroutine lis_array_matvect(LIS_INTEGER n, LIS_SCALAR a(), LIS_SCALAR
x(), LIS_SCALAR y(), LIS_INTEGER op, LIS_INTEGER ierr);

that's her. that's the whole signature. iconic behavior fr fr 💅

🌸 DESCRIPTION 🌸

so literally what she does is calculate the matrix-vector product A^Tx. that's it. that's the assignment. and she ate. 🔥

🎀 INPUT 🎀

• n — the size of the matrix and the vectors. like, how big we're going. 📏
• a — the array that stores matrix A, and it's size n * n. big girl matrix energy. 👑
• x — the array that stores vector x, size n. 🦋
• y — the array that stores vector y, size n. 🌸
• op — the vibe selector, choose your fighter:
  • LIS_INS_VALUE — gives you y = A^Tx. fresh, clean, brand new y. ✨
  • LIS_SUB_VALUE — gives you y = y - A^Tx. she's subtracting, she's doing math, she's in her era. 💀

💜 OUTPUT 💜

• y — y. that's the output. that's it. y is y and y is served. 🙈

🌈 SEE ALSO 🌈

• lis(3)
• http://www.ssisc.org/lis/

heads up bestie: op only knows those two moves, so pick one of LIS_INS_VALUE or LIS_SUB_VALUE and don't be out here inventing new ones, okay? 🫶

and that's the whole page, no notes. this gem is from the Lis Library Functions, dated 3 Dec 2014, and the man page signs off as lis_array_matvect(3f). slay, stay hydrated, go multiply something. 💖✨🎀