Mathematics - 2020-10-05 (page 2 of 2)

Balarka Sen

20:00

only rich people do it because they have nothing else to do

therefore i promote a future where everyone equivocally bans math

pure mathematicians are redundant human beings; even continental philosophers are more productive than them

math is Dead - Nietsen

Rithaniel

Balarka obviously just was dumped by a mathematician

Balarka Sen

exposed

Edward Evans

Banter

Rithaniel

Darn in/surjectivity, and how useful they are as properties.

Edward Evans

I just discovered that I „hAvE tO tAkE a MoDuLe In ApPliEd MaThEmAtIcS“

Rithaniel

20:14

I've never used a non-injective, non-surjective function in any proof, and so don't know how to do anything with them

Applied modules?

Alessandro Codenotti

@EdwardEvans rip

Edward Evans

Lol as in, a course in applied maths

It’s usually 3 courses but you can register your „applied area“ as pure mathematics hahaha so you can drop the other two applied courses and then you only need one

I‘ma just take probability theory

Rithaniel

Applied set theory: "I have three apples."

Edward Evans

„There are probably three apples“

Rithaniel

"The number of apples I have is in direction bijection with the number of hands I have to hold them (plus an error of plus or minus one hand)"

Edward Evans

20:19

Damn

Balarka Sen

@EdwardEvans yiss

Rithaniel

Statistics: "There is a 75% probability of there being a 65% probability of the measure being accurate to within 15% of the true value."

Balarka Sen

almost accurate

Alessandro Codenotti

@EdwardEvans What are the other options?

Edward Evans

21:01

I think PDEs would be another option since I took a PDE course in my bachelor, but probability theory will include measure theory and I need to force myself to do some analysis

Thorgott

analysis is nice in small doses

Edward Evans

I think it probably is but so far I only found complex analysis nice

real analysis seems so nerdy

user2103480

what about semigroup theory?

that functional analysis applied to PDE course

heidelberg it was, right

Edward Evans

right

user2103480

@AlessandroCodenotti took a course on semigroups if I recall correctly

Edward Evans

21:06

yeah I mean, probability theory doesn't seem that bad, and I did a lot of statistics and probability in my bachelor (which I immediately forgot post-exam every single time)

user2103480

well

you can also do this one if you want some ML mumbo jumbo to spice up your credentials, if someday you may decide against academia

hci.iwr.uni-heidelberg.de/content/…

Edward Evans

The bachelor's degree here is easily at the level of any master's degree in the UK outside of Oxbridge tho, so even bachelor level probability theory will be hard rofl

yeah I saw that too

user2103480

the course contents dont seem that bad prerequisite-wise

Edward Evans

It's not for this semester anyway, I'm "fully-booked" this semester

but the next couple of semesters after this one will be fairly relaxed so I'll probably stuff some applied courses in there hahaha

user2103480

ah ok then its not possible to plan anyways

Edward Evans

21:09

Right, but I know that probability theory comes in the summer semester

user2103480

@EdwardEvans at my old uni, cologne, probability was most students' nemesis

Edward Evans

loool fair

Are you in Heidelberg?

user2103480

Nahh FU Berlin's my uni now

William Torkington

Do either of those do bachelors in English?

Edward Evans

Ah okay :)

Heidelberg does not

in fact I think it's fairly uncommon for German unis to offer bachelor's degrees in English

user2103480

21:11

yeah, but master's often are

except for cologne because cologne math is shitty tbh

William Torkington

True. I want to study in Germany but I have a bachelors in computer science, so I've been considering either doing a bachelors in math or a masters in computer science, but I really just want to do math and not computer science.

Really? Like University of Bonn? I thought they were pretty good for math.

user2103480

bonn might be an exception

But I think even there the analysis cycle is in german

William Torkington

Well, darn. Duolingo it is I guess

Are you all doing your bachelors or masters atm?

Edward Evans

I'm doing my masters

Thorgott

undergrad probability isnt bad

William Torkington

21:18

Probability made more sense to me when it connected distributions to integration.

user2103480

@Thorgott if you're quick you can do SPDE in your 6th semester in germany, i.e. in your bachelor's lol

ah no just SDE in semester 6. For SPDE you'd have to wait for semester 7, since most probability cycles start with what you probably meant as "undergrad probability" in semester 3

nonetheless, it starts early and gets messy quick. But nothing's as bad as bonn's topology 1 - 5, which is just insane

Thorgott

I did undergrad probability (Elementare Stochastik) in my 2nd

one of my friends does a lot of probability for his masters and he showed me some SDE stuff, definitely wouldn't wanna do that

Alessandro Codenotti

21:41

@user2103480 I did, it was a semigroups of operators course

@WilliamTorkington Bonn teaches in German at the bachelor level (except for courses that can be taken by masters students as well) and in English at the masters level

Edward Evans

22:07

I found a stupid factory building game and now I'm just playing that instead of studying

Alessandro Codenotti

Factorio?

Satisfactory?

Which rabbit hole have you fallen into?

Edward Evans

Nah I played that for a while, but this one is called shapez.io

Alessandro Codenotti

Never heard of that

Edward Evans

shapez.io is just factorio but in easy af

there's different kinds of shapes and you cut them and colour them and stack them in different ways and then deliver them to a hub in order to get upgrades

Alessandro Codenotti

Just like factorio I'll use all of my force of will to never open it then

Edward Evans

22:08

but it's all about ratios and automation

hahahaha

Factorio is a true degree-killer

Alessandro Codenotti

I'll never get anything done anymore otherwise

Balarka Sen

come we'll play Among Us

lol jk

Edward Evans

rofl

Alessandro Codenotti

I'm avoiding that too lol

Balarka Sen

we all should play it

someday

Edward Evans

22:09

analyst lookin' sus

Alessandro Codenotti

I've been playing the Talos Principle lately, pretty neat game

Edward Evans

idk that game

Alessandro Codenotti

It's a single player puzzle game with philosophical elements

Thorgott

Talos Principle is really neat

Balarka Sen

Thorgott

22:11

I should finish it some day...

Balarka Sen

kindasus.jpeg

Edward Evans

Ah, Talos from Greek mythology, not Talos the god from the elder scrolls universe

Sounds kinda like the witness

Balarka Sen

I have to get Disco Elysium

Edward Evans

Also listen to Cattle Decapitation - Death Atlas. I know I tagged y'all already but SERIOUSLY it's amazing

Balarka Sen

cattle decapitation is too much on the side of death metal for me

GOREGRIND

eh

Edward Evans

22:16

I know it sounds like that

but

that album is genuinely incredible

not goregrindy grindcorey bullshit

Balarka Sen

hmmm ok

Edward Evans

it's like black metal + deathcore

Balarka Sen

kinda sus but i buy it

Edward Evans

definitely give it a try

Balarka Sen

oh black metal

Alessandro Codenotti

22:17

@EdwardEvans it's like the witness if the witness had a real story and no bs ending

Balarka Sen

let me see

Alessandro Codenotti

@BalarkaSen I've heard great things about it

Edward Evans

@Balarka I recommend the song "Bring back the plague" as a taste of the album

to give you a good impression

Balarka Sen

fanks, first thing in the morning tomorrow then

Edward Evans

nice wun

dude's vocals are insane

Balarka Sen

22:18

relevant lyrics

Edward Evans

oh yeah all their music is about humans destroying the earth and shit

it's like Gojira on steroids

Alessandro Codenotti

W H A L E S

Edward Evans

hahaha

Balarka Sen

lolol

Alessandro Codenotti

Gojira is good though

Balarka Sen

22:20

such a great album tho

Edward Evans

aye

Balarka Sen

how did they come upon the lovecraftian imagery of whales flying in the sky

Edward Evans

they should do a re-release that is just whale song tuned to various pitches

Alessandro Codenotti

Balarka Sen

LMAO

Edward Evans

22:21

haaaaaaaaaa

Mike Miller

wait is there a spongebob ep where he makes the king crimson face?

Balarka Sen

Steven Wilson is no longer sad SpongeBob

he's putting out banger disco music

check it out

Alessandro Codenotti

@MikeMiller I'm no spongebob expert, sorry

Not sure if it is from an actual episode

Balarka Sen

that'd be hilarious

Mike Miller

I looked at the art, def not

Amin Idelhaj

22:26

What's up nerds

Edward Evans

wagwan

Amin Idelhaj

How's it going

Edward Evans

living the dream

Balarka Sen

Nerdoid appeared out of the void

Edward Evans

hbu

William Torkington

22:33

@AlessandroCodenotti Thanks! Guess I should start practicing then :,)

Amin Idelhaj

God I've got so much shit to do this week

Alessandro Codenotti

I don't know exactly what the language requirements for a bachelor in Bonn are, since they are very lax on what counts as proof of English proficiency for the masters, but most German institutions require the so called TestDaF or equivalent

There's also the option of doing bachelor anywhere else and a masters in Germany of course

Edward Evans

@Amin rip

William Torkington

I know. That's like C1 proficiency which I definitely cannot do in 11 months haha.

I already have a bachelors in Computer Science, but I really just want to go back to uni for math, cause it is way cooler imo. I have to look into if I can do a masters in CS while also doing a bunch of math papers, or what.

geocalc33

Anyone know off the top of their head what the equation is for a smooth polar zonohedron?

Thorgott

22:40

I'd be concerned if anyone does

4

nbro

3

Q: What are some best practices when trying to design a reward function?

Generally speaking, is there a best-practice procedure to follow when trying to define a reward function for a reinforcement-learning agent? What common pitfalls are there when defining the reward function, and how should you avoid them? What information from your problem should you take into con...

user2103480

@WilliamTorkington I can definitely not recommend the bonn CS master theory-wise

Alessandro Codenotti

Just enrol in the math one and do combinatorial optimization

user2103480

maybe their optimization & integer programming courses are better, but anything data-sciency etc is frankly horrible

William Torkington

@user2103480 That is actually really good to know. I would definitely be specialising in ML if anything master-wise.

user2103480

22:48

haha, ML is horrible anywhere tho

maybe the practice stuff is OK but even a lecturer in statistical learning theory told me "avoid computer scientists' courses"

William Torkington

@user2103480 I feel like it's just a lot of linear algebra, calculus and stats tbh, so if I just did a lot of those I'd be able to do ML, you know?

user2103480

It's mostly shallow applications of the theory and mentioning the main theorems

William Torkington

Hahhaha classic

user2103480

Most classes are memorization-heavy and mathematically subpar in notations and definition

interpolated from basically every CS class I've ever had and those were like 6-7

including 3 on data science at two universities

William Torkington

yeah, same at my uni tbh

user2103480

22:53

And if it is actually mathematical, then it's glorified optimization and a bit of rademacher complexity, which is useful but ugly.
There are some nicer courses on mathematical aspects/foundations of ML and deep learning, but not many

@WilliamTorkington Ah. A new thing to me was the amount of material compared to the short time in exams, in the data science courses. Other students told me it's that way in most classes. Gotta write like a berzerk to finish with a good grade

William Torkington

Right, well all of my exams have been 3 hours I think, so maybe it's not so bad here. Yeah, exactly the optimisation stuff. It's all very hard to understand coming into it blind, but once I actually looked into the math behind it it was much easier to understand.

What are you studying currently?

user2103480

continuous stochastics processes are the main focus, with an "applied" focus. So next semester will be SPDE, stochastic processes in fluids (statistical mechanics), and stochastic processes in neuroscience (hodkin-huxley-model and such). Also a course in topology.

But in the last semesters I took some logic courses and a few data science/NLP things. Thought I might do some probabilistic stuff in AI, but the current methods didn't seem so mathematically appealing

William Torkington

cool. Don't know what most of that means but cool. All they have at my uni for undergrad is probability, calculus, linear algebra, and discrete math, and that's about it.

user2103480

did you already have some proof-based courses?

programs vary a lot in that regard

Mike Miller

@AminIdelhaj Why are you here

William Torkington

23:09

Hmmm, honestly not 100% sure. I learn a lot of proofs of theorems, and I've learnt about induction, contradiction and that, if that's what you mean @user2103480

user2103480

that's just what I meant

Balarka Sen

@MikeMiller Just to suffer

William Torkington

@BalarkaSen lmao

geocalc33

After further reading: A smooth polar zonohedron is the surface of revolution created by a rotation of a sine curve

Dirichlet

23:37

Is f(x) = |cos2x| differentiable at $x=\pi/4$ . I think no , but my book says yes.

Mike Miller

23:54

Nah it's not I agree with you

Say f(x) has f(a) = 0. If f and |f| are differentiable at a then f'(a) = 0. (Proof is 1st order taylor expansion)

But cos(2x)' = -2sin(2x) which evaluates at pi/4 to -2, so |cos(2x)| can't be differentiable at pi/4.

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$Mathematics$ Mathematics