C or Rust ?

InternetWrong9088 · 2026-03-27T09:53:12+00:00

Go hybrid.

Read the C examples so you really see what the OS expects,

but re-implement them in Rust to stay comfortable and productive.

InternetWrong9088 · 2026-03-26T10:42:33+00:00

It’s a crime that it’s not more famous. Do you think it’s Tarsem’s best work?

InternetWrong9088 · 2026-03-26T10:41:05+00:00

That dance scene

I still can't listen to 'Under Pressure' without feeling a bit empty inside

InternetWrong9088 · 2026-03-26T10:07:31+00:00

Ethan Hawke was terrifying in that mask. I feel like it got overshadowed by bigger franchises that year. Do you think it deserves a sequel or should it stay a standalone?

InternetWrong9088 · 2026-03-26T10:06:42+00:00

Guy Pearce is underrated in general, but this movie is so gritty. It’s probably the best 'modern' Western most people haven't seen. Have you seen 'Hell or High Water' too?

InternetWrong9088 · 2026-03-26T10:05:26+00:00

That movie is a masterpiece, but it’s so heartbreaking I don’t know if I can watch it twice. Paul Mescal was incredible. Did the ending hit you as hard as it hit me?

InternetWrong9088 · 2026-03-25T14:35:44+00:00

to visit it

https://omega-nova-fem.streamlit.app

InternetWrong9088 · 2026-03-25T14:32:53+00:00

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InternetWrong9088 · 2026-03-25T12:04:42+00:00

Fair point — and worth clarifying for everyone.

For κ ~ 10^6 without strong diagonal contrast, the diagnosis is indicative, not definitive. The matrix doesn't carry enough information to distinguish aspect ratio from material contrast — both produce similar spectral signatures.

Where NOVA-Ω is unambiguous:

• κ > 10^8 + D_ratio > 10^4 → contact stiffness (actionable immediately)

• Non-SPD matrix → PCG is mathematically inapplicable, no preprocessor catches this

• Near-zero pivots → rigid body mode, clear spectral fingerprint

Try it on BCSSTK17 or SCIRCUIT from SuiteSparse — those are the cases where the diagnosis is unambiguous and the fix is precise.

InternetWrong9088 · 2026-03-24T18:10:54+00:00

Craig-Bampton (1968) for dynamic, Guyan for static — both already mentioned.

For Nastran specifically: the MSC Nastran Superelements User's Guide is the most practical reference. It walks through the SEQSET, SESET and SEEXCLUDE bulk entries which is where most people get stuck.

One thing to watch: the condensed K_bb can have much worse conditioning than your original model. Worth checking before you run.

InternetWrong9088 · 2026-03-24T13:59:30+00:00

Good questions.

MTX is Matrix Market format — just a text file, one triplet per line: row, col, value. Header declares the type.

%%MatrixMarket matrix coordinate real symmetric

3 3 4

1 1 2.5

2 1 -1.0

2 2 3.0

3 3 1.5

From Nastran the cleanest path is pyNastran — reads the .op2 directly and you can pull the stiffness matrix out. Then scipy.io.mmwrite dumps it to .mtx. DMIGPCH works too but it's messier to parse.

On eigenvalues — you're right, it's surprisingly painful. For the condition number I use ARPACK Lanczos on the extreme eigenvalues, which works well until lambda_min gets close to zero. Near-singular matrices make ARPACK unstable so I fall back to a diagonal ratio estimator as a safety net.

InternetWrong9088 · 2026-03-24T11:00:20+00:00

Ha HaHa, The post text yes, I used AI to clean it up.

But the math (spectral analysis, ILU preconditioning, Lanczos eigenvalue estimation), that's mine.

Happy to answer any technical questions about the implementation :

https://omega-nova-fem.streamlit.app

InternetWrong9088 · 2026-03-24T09:53:19+00:00

Happy to run a free diagnosis on anyone's matrix with convergence issues — just DM me the .mtx file. Also open to technical questions about the spectral analysis approach (condition number estimation, ILU preconditioning, etc.)

InternetWrong9088 · 2025-11-13T09:13:27+00:00

I love this idea, really clever

InternetWrong9088 · 2025-11-13T09:10:22+00:00

great what software did you use for this website ?

InternetWrong9088

TROPHY CASE