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I'm combinating Why's.

Nikolaj Kuntner Nikolaj-K

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I'm combinating Why's.
  • DLR Germany, IST Austria, Infineon, ...
  • Vienna
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@Nikolaj-K
Nikolaj-K / scalargrad.py
Last active October 23, 2023 21:31
A simple implementation of reverse accumulation (back-propagation)
"""
Impelmentation of reverse accumulation (backpropagation), discussed in
https://youtu.be/BcCk8I6YAqw
Most of this script is exposition code. The reverse accumulation code still runs if you delete everything except the following 5 classes
* ValAndDVal, ExprBaseRevAcc, VarExprRevAcc, PlusExprRevAcc, MultExprRevAcc
validated using the following 2 functions:
* p, run_VarExprRevAcc_gradient_decent_demo
@Nikolaj-K
Nikolaj-K / bandit_strategies.py
Last active October 10, 2023 15:59
A small pytorch routine approaching the n-armed bandit problem
"""
Casino strategies and some pytorch. The code is explained in the video
https://youtu.be/VUVVVi9CgbI
I think you can install pytorch via `pip` or `pip3` through
`pip3 install torch torchvision`
Some mathy reading material:
* http://yuanz.web.illinois.edu/teaching/IE498fa19/
@Nikolaj-K
Nikolaj-K / zolotarev.py
Last active September 16, 2023 22:36
Zolotarev's lemma
"""
Code discussed in the video:
https://youtu.be/0A3mAUGFUow
* Motivation:
- Relation between Legendre symbol and quadratic equations on ZxZ
+ See https://en.wikipedia.org/wiki/Legendre_symbol#Table_of_values
* For any fixed number, validate
@Nikolaj-K
Nikolaj-K / copious_secret_santa.py
Last active August 19, 2023 18:01
Copious Secret Santa / Voting assignment
"""
Script used in the video
https://youtu.be/2b9fOpX0zKY
Formal structure: balanced simple digraph
(Important special properties out-degrees equals the in-degrees, no self-loops, no parallel arrows)
1. Proof task: Count them, given any assginment of out-degrees.
How does it compare to just random disgraphs with that those out-degrees?
1. Coding task: Generate one given the out-degrees, fast. (I have a bad, probabilistic solution)
@Nikolaj-K
Nikolaj-K / make_voting_assignment.py
Last active October 28, 2023 10:40
Create a HV-MT voting assignment based on a list of capacities
"""
Scirpt discussed in video here:
https://youtu.be/2b9fOpX0zKY?si=hjztP-RAwIgq_Yed
HV-MTL Voting assignment based on users with different voting capactities per day.
More formally: Generation of a balanced simple digraph* (and corresponding plot)
based on a vertex set and their number of outgoing edges,
with a high number of opposing edges (reciprocated votes percentage is a config).
@Nikolaj-K
Nikolaj-K / constructive_arithmetic_freebies.md
Last active September 23, 2023 12:14
Four freebies of constructive arithmetic
@Nikolaj-K
Nikolaj-K / absorbing_markov_chains.py
Last active October 1, 2023 12:06
Absorption probabilities in finite Markov chains
"""
Code used in the video
https://youtu.be/BiViLT6FCC4
"""
import random
import numpy as np
class LinAlgLib: # Linear algebra'ish functions
@Nikolaj-K
Nikolaj-K / regularity_vs_induction.md
Last active November 8, 2022 01:24
Regularity versus Induction

Text used in this video:

https://youtu.be/7HKnOOvssvs

==== Recall the regularity statement ==== $\forall s.\Big(s\neq{},\to,\exists(x\in s). x\cap s={}\Big)$

==== Logical definitions and theorems ==== === Definitions ===

@Nikolaj-K
Nikolaj-K / regularity_nonstandard.md
Last active September 7, 2022 13:51
Regularity and non-standard models of arithmetic #PaCE1
@Nikolaj-K
Nikolaj-K / choice_implies_lem.md
Last active August 16, 2022 23:35
AoC => LEM

Text used in the video

https://youtu.be/2EOW23uVcRA

==== ==== ==== ==== ==== ==== ==== ==== ==== ==== ==== ==== ==== ====

Theorem: ${\mathrm{Axiom\ of\ Choice}}$ implies ${\mathrm{LEM}}$

More concretely: If equality is governed by set-extensionality, then for any predicate $P$ allowed