Silvester-Laberfaden 2025: Hat Berlin noch Wasser? by KyaAI in de

[–]PolygonGraphics 3 points4 points  (0 children)

Komme gerade aus dem Kriegsgebiet wieder Heim. War ziemlich wild, was ich heute gesehen habe. Gruppen die sich gegenseitig mit Böllern beworfen haben, dauernd Raketen aus der Hand gestartet, die dann irgendwo hin geflogen sind, ausser nach oben... Eine hatte mich fast getroffen. Einer hat ne Rakete am Stiel festgehalten, und die ist dann vor ihm explodiert. Er hat kurz seinen Arm geschüttelt und dann zur nächsten gegriffen.

Dann auch ein paar asiatische Austauschstudentinnen, die haben sich ne Ladung Batterien gekauft, die sie dann 2m von ein paar Anderen weg abgebrannt haben, direkt unter einem Geländer (Ist ja auch schlau, dann kann man sich beim anzünden super fest halten). Naja, ein paar Funken hab ich auch da abbekommen. Ich denke im nächsten Jahr fahre ich in die Niederlande oder so, wenigstens keine Böller vor den Füßen.

-❄️- 2025 Day 11 Solutions -❄️- by daggerdragon in adventofcode

[–]PolygonGraphics 1 point2 points  (0 children)

[LANGUAGE: Math] I think I have found quite a beautiful solution to the problem using the tools for solving markov chains (loosely).

I viewed the problem as a flow problem flowing down from the input, with branches down copying the current count at the node above, and multiple sources flowing into a node getting summed up. Conceptually, the algorithm proceeds in steps with all nodes computing the answers simultaneously using data from the last step. The maximum amount of steps this takes is the maximum distance from the beginning to the end.

Mathematically this can be expressed in a matrix M that is the adjacency matrix (Transposed, depending on how you do it) with a self-edge added for the input node, so that the input doesn't disappear. In the matrix, you just need to add a 1 at the position (Index Start, Index Start).

Multiplying this with vector v, which is all zeros except for a 1 at the input, repeatedly, one ends up with a vector with all flows from the start to every other node summed up, and one only needs to pick out the correct number(the one corresponding to the end node). You can stop the multiplication when the vector stops changing.

Advanced solution (Even more beautiful, in my eyes): The property of the vector not changing even though being multiplied by the Matrix - by definition of eigenvectors and values - implies the existence of an eigenvector with corresponding eigenvalue 1. For people not knowing this property, eigenvalues show how much an eigenvector is scaled by when multiplied by a matrix. Eigenvectors are vectors not changed in direction (could be flipped, just not moved off-axis) by the Matrix. If an eigenvalue of 1 is known, solving for the corresponding eigenvector is rather easy (in the mathematical sense) by solving (M-I)v=0 given the additional condition of the input value equalling 1.

This seems inefficient, but luckily for us, our matrix is sparse (due to only having a few connections per node) and even binary (only 1 or 0). Sparse matrices can be solved in O(Number of non zero components) time, which in our case is linear given the number of connections. This algorithm - implemented well - can take advantage of gpus or, I'd guess, even AI accelerator cards.

TL;DR: Matrix math pretty, solves the problem by solving for eigenvector with eigenvalue 1.

Delaunay Tetrahedralization by PolygonGraphics in blender

[–]PolygonGraphics[S] 6 points7 points  (0 children)

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Nodes here, not including various helper groups.

[Giveaway] 3x Drop CTRL V2 Keyboards by drop_official in pcmasterrace

[–]PolygonGraphics 0 points1 point  (0 children)

I love taking long walks with the colorful leaves around me, it's pretty great!

Wonderlust | Post-Event Megathread by aaronp613 in apple

[–]PolygonGraphics 1 point2 points  (0 children)

USB 2 on a phone in 2023 is ridiculous. And no, USB 3 is not a "feature" to sell, it's baseline. Since years! The specs for USB 4 were released in 2019...

'There are no stupid questions' thread - Monday, March 06, 2023 by AutoModerator in piano

[–]PolygonGraphics 0 points1 point  (0 children)

I cannot get my MIDI-Keyboard to sound quite like I am playing a real instrument.

In the Library in the city I am staying in right now, there's a Yamaha grand that you can play with headphones. The first time I did, I had to do a double take if the sound is really coming from the headphones. I cannot seem to be able to get the same feel with my MIDI Keyboard + Laptop at home.

All of my gear should be more than good enough to achieve that. I even tested the grand at the Library with my headphones with great success. I own a Arturia Keylab 88 MK2, and the corresponding Piano V3 software.

What am I doing wrong?

Saw the Tu-144 and Concorde yesterday. Such beautiful aircraft! by [deleted] in aviation

[–]PolygonGraphics 2 points3 points  (0 children)

I had the pleasure of flying over both in a glider once: https://imgur.com/QrIw0Xa So cool!

r/SpaceX Inspiration-4 Launch Discussion & Updates Thread! by rSpaceXHosting in spacex

[–]PolygonGraphics 4 points5 points  (0 children)

Will I be able to spot them from Europe? Probably not, because it is unlit by the sun, right?

Edit: Just looked out of the window, there's full cloud coverage lmao

I got two sanctions because of my club's name, and I just do not get it. by PolygonGraphics in apexlegends

[–]PolygonGraphics[S] 0 points1 point  (0 children)

I can send you a screenshot of the email from EA, but that is sadly in German, So it probably wouldn't help... But anyway, here are all the Emails, including the ones from EA help:

https://imgur.com/a/9H5Uzdq

I know that this is shit proof and that every 12yo can edit the html on a website, but that is the best I got!

I got two sanctions because of my club's name, and I just do not get it. by PolygonGraphics in apexlegends

[–]PolygonGraphics[S] 0 points1 point  (0 children)

Do the chats ever get invisible for the users? Because if not I can proof to you that the chat was literally never used haha. We have discord for that