lis_esolve(3)

✨ lis_esolve — solve the standard eigenvalue problem ✨

okay bestie, welcome to lis_esolve(3) from the Lis Library Functions 💜 — yes this is the one where we find eigenvalues, and yes it's giving main character energy 🔥

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🌸 SYNOPSIS 🌸

#include "lis.h"

LIS_INT lis_esolve(LIS_MATRIX A, LIS_VECTOR x, LIS_REAL evalue,
LIS_ESOLVER esolver);

literally copy that verbatim, no cap 🫶

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💖 DESCRIPTION 💖

so what this does is solve the standard eigenvalue problem Ax = lx using whatever eigensolver you hand it. that's it. that's the whole vibe ✨ you give it a matrix and an initial vector, it gives you back an eigenvalue and the matching eigenvector. iconic behavior honestly 👑

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🎀 INPUT 🎀

• A — the coefficient matrix 🧮 the whole point of the operation, lowkey
• x — the initial vector 🌱 where the iteration starts its little journey
• esolver — the esolver 💅 the actual solver doing the heavy lifting

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🦋 OUTPUT 🦋

• evalue — the eigenvalue of mode 0 ⭐ mode zero specifically, don't forget
• x — the associated eigenvector 🌈 the one that belongs to that eigenvalue
• esolver — the number of iterations, the execution time, etc. ⏱️ all the receipts, bestie

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💀 EXIT STATUS 💀

here's what you get back:

• 0 — the process is normally terminated 🎉 we ate
• unspecified — an error occurred 😭 something went wrong and it's not telling you exactly what

ngl, "unspecified" is not the most helpful thing in the world but that's literally what it says, so. we report, you decide 🙈

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🔥 SEE ALSO 🔥

• lis(3) — the main character of the manual set 👑
• http://www.ssisc.org/lis/ — the website, go look at it 🌐

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that's the whole page, bestie, you're so welcome 🫶✨

this was Man Page, dated 23 Oct 2016, for lis_esolve(3) — catch you in the next one 💜🎀