lis_solve_kernel(3)

💖 lis_solve_kernel(3) 💖

okay bestie, come SIT. this is a page from the Lis Library Functions manual, and it's about lis_solve_kernel — the girl who solves your linear equation for you with a preconditioner you already set up. she's lowkey the moment, fr fr. 🌸

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✨ NAME ✨

lis_solve_kernel — solve the linear equation with the predefined preconditioner 🫶

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✨ SYNOPSIS ✨

#include "lis.h"

LIS_INT lis_solve_kernel(LIS_SOLVER solver);

like, that's it. one function, one arg. she's serving minimalist. 💅

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✨ DESCRIPTION ✨

so the whole vibe here: she solves the linear equation using the solver you picked and the preconditioner that was already defined ahead of time. no extra setup at call time, no drama, she just goes. 🔥

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✨ INPUT ✨

here's everything going in, bestie, don't lose track:

• A — the coefficient matrix 👑
• b — the right hand side vector 🌈
• x — the initial vector ✨
• solver — the solver 💜
• precon — the preconditioner 🎀

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✨ OUTPUT ✨

and here's what comes back out:

• x — the solution 🦋
• solver — the number of iterations, the execution time, etc. ⭐

not me casually returning the iteration count AND the timing, she's so considerate 😭

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✨ EXIT STATUS ✨

these are the exit values, keep them in your notes:

• 0 — the process is normally terminated 💖
• unspecified — an error occurred 💀

yes, "unspecified" is literally the value. we don't know what happened, and honestly? neither does she. 🙈

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✨ NOTE ✨

want an example? go peek at lis-($VERSION)/src/esolver/lis esolver ii.c, which computes the smallest eigenvalue by calling lis_solve_kernel multiple times. that's the girlboss reference implementation, iykyk. 👑

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✨ SEE ALSO ✨

• lis(3) 🌸
• http://www.ssisc.org/lis/ 🌐

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and that's the whole page, bestie — no cap, every flag and every line stayed exactly where it was supposed to be. mwah. 💅

source & version: Lis Library Functions · date: 6 Sep 2012 🎀 bye ily 🫶