poor indeed

@meer2kat you don't need to make math contributions to be in here

most of us don't most of the time

yeah i can tell

I just come here to troll @mike.

you're not very good at it @Jasper

The original question? To compute $\tau (K_{3,m})$

@meer2kat so are you going to take pure math?

@Studentmath think of equivalent choices

probably not. i'll do regular and save myself $8000

you're in CS, I take it?

@meer2kat :(

Thanks @ccorn! probably that, didn't think about it

that or coen

@mike, who? me?

da

nah, i'm currently mechanical engineering

and i'm switching to get my bachelor's in mathematics and my M.A.T.

neat

know what you want to do with it?

teach middle school math

then go back to engineering one day

I want to calculuate 1+1=2, lol.

:)

:)

:)

:)

lol

:D

anyone here enjoy manufacturing information and physics?

@ccorn would it be right to say that since every given choice of the two possible in the second vertex is already included in the choosing of the options of the first vertex, it's only (m-1)?

@meer2kat You look pretty.

can't decide if trolling or true compliment

I was always knew that JasperLoy would give that compliment...

@Studentmath Consider the result of your choosing. Somehow each must be equivalent to another one. That causes division by two, and you get your result.

@meer2kat Well, I only speak the truth.

@ccorn Alright, many thanks!

@Hawk He meant me

lol

@ccorn he meant you to be pretty??

I wish I can go back to my undergrad days. I will do that next life.

@Hawk Do you see any other avatar where everything is in place? (OK, just kidding)

@JasperLoy really...life's over...we are really dead and old ghosts...waiting for next life...

@ccorn no, i don't (I know you're kidding)

@Hawk I really do believe in rebirth. I hope to be born in Germany my next life, lol.

@JasperLoy hmm, I prefer to be never born...I want to be ghost with supernatural powers....that would be much more fun!

$380.00 for a seal ring....that's impressive

@robjohn About the downvote you got today: This morning somebody serially upvoted +9 scored answers of Bill Dubuque, Henning Makholm, and me. The downvote you got came six seconds after the upvote on my answer to that question, so I'm almost willing to bet that it was the same person. If you're interested enough, you could see whether other competing answers to one of the serially upvoted got a downvote in close proximity to the upvote, wouldn't surprise me.

@Hawk Then that is you reborn as a ghost, not a human.

@DanielFischer Many crazy people on this site, lol.

@JasperLoy Indeed.

Of course, I am also crazy, as most know.

@DanielFischer Hmm... I was thinking that someone was upvoting those with less reputation, and downvoing those with more. However, if Bill got upvoted, that contradicts my hypothesis.

@robjohn I wonder which enemy you made...

@JasperLoy I really don't know what I would have done to aggravate anyone. There are some people that I've had to come down on as a moderator, but so do all the mods and none of the others have gotten serial downvotes.

@robjohn Interesting. Mechanically that would amount to "damping".

@robjohn Maybe it is the same person who downvoted me three times.

@robjohn None of Bill, Henning or me does exactly invite upvotes because somebody else has a wee bit more rep. Though of course there are people who have more.

@ccorn leveling the playing field?

hm

Should there be any system where if anyone is serially downvoting, the user will be visible to moderators?

@DanielFischer not many have more than Bill

wait so no one can see who's downvoting? i assumed that mods could

@Hawk Currently only the SE staff sees every vote.

@robjohn Not many have more than Henning or I either.

@meer2kat They are only alerted when there is too much downvoting.

@DanielFischer That's true...

@meer2kat Why did you choose this username?

@JasperLoy so, why don't they control that?

@robjohn The serial upvotes will certainly be revoked by the script. Is there a chance that downvotes from that spree will be revoked too?

@Hawk It's hard to decide if a vote is "genuine" or not.

@robjohn Something like that. Though those persons probably do not participate the usual way. In that sense, it's not a playing field for them, just a medium that they make more conductive.

@meer2kat the community team can see. Since the mods participate on the site, it would seem odd if the mods could see who downvoted them.

ah

been my username since i was 7 jasper

@JasperLoy so, why should not serial votings be visible to moderators too?

@meer2kat What's your real name anyway?

I knew JasperLoy would ask this question too...

@Hawk If it passes a certain threshold, mods will know automatically.

@Hawk Hehe, what do you know about me? Confess!

alyssa...

Okay, so should the threshold value be decreased in that case?

@meer2kat That's a lovely name.

thanks

@JasperLoy I know nothing about you, but can interpret human behaviour.

@Hawk It cannot be decreases because we cannot determine if a vote is "genuine".

Got it :) thanks!

thanks lol

Many people I used to chat with here have left: Jonas, math101, etc.

including you

@JasperLoy People cycle in and out.

I just emailed Jonas.

He is still alive, lol.

@robjohn I can't cycle, lol.

@JasperLoy then use training wheels.

you can tri

@robjohn I should get a tricylce, but everyone would laugh.

@Studentmath Excellent! Just a thing: If you describe the problem or the solution in math terms, better don't use group. Set might be a better fit here. Abstract algebra concepts, you know.

Yes, sorry about that. We don't have distinct word for the two terms in Hebrew afaik, so I constantly get it wrong in English :)

@meer2kat this is a wild guess, but do you live somewhere in australia?

crikey no

@Studentmath Woha. If I recall correctly, $\nabla$ (nabla) is from hebrew.

i'm in indiana/kentucky/virginia depending on the time of year. i move between three places a lot

where do you go to school, if you don't mind me asking?

It's from Greek, but it is the hebrew word for harp (hence the symbol)

not creepy at all

lol

well, we just lost in the sweet 16

Has OldJohn been here recently? I haven't seen him, but that could be because our times interleave.

and i live in kentucky

@robjohn nope

i wasn't aware small talk was creepy :P

should be able to figure it out XD

@Studentmath so now I have learned something from you.

only one team that fits that

Depends on your definition of creepy.

well, i wasn't aware there's more than one team in kentucky

Never imagined that could happen :P But glad to be of use!

there are two mike

@Mike I see that he was here on March 20.

UK and UofL

I have creeped several users in chat before, lol.

UofL lost sweet 16

cries

After sweet 16 comes stale 17.

@robjohn That's too long ago to be recently :)

time to go home...might pop on from home computer. not sure. i have to get to playing stronghold kingdoms...

later

@meer2kat Bye! See you in your dreams, lol.

there are better games to waste your time on

@Mike Such as chess.

@mike....it's an addiction. play for about a month and you'll be hooked too. people spend thousands of dollars and years playing

chess is great

i used to be on the chess team

anyways

Me too.

gtg

see ya

:)

I just had a terribly sweet chocolate cake. I will die from sweetness.

@mike Have you decided which school you will be going to? You can email me.

@Mike a couple of weeks.

@robjohn I do believe my three downvotes come from the same user, maybe he used multiple sockpuppets.

@skullpatrol that is so non-descript... what are you going to say: earlier?

@JasperLoy you only have three? wow.

@robjohn I mean on those three consecutive days. There are others.

@JasperLoy Ah, I have 42.

@robjohn That's very few, considering you have 100k.

One did get removed when a user left or perhaps they rescinded.

@JasperLoy I try to write decent answers. If I make a mistake, I will correct or delete.

I have concluded that the majority of MSE users are not very good in math, so they often upvote answers that are not good and downvote answers that are good.

@robjohn I try to write correct answers to ground fruit.

I have concluded that although SE strives to attract experts, the majority of high rep users are not truly experts.

My laptop is down to 43% battery. I need to think about moving closer to my charger.

The true experts are too busy doing things in real life instead of coming online for some silly rep points.

@JasperLoy a lot don't think this is a good use of their time, but I think it is a good place to explain things that I've learned.

@robjohn I see. Sigh, you should have stayed on as a professor. The math world is less without you!

Does anyone know who Andre Nicolas is in real life?

@robjohn and we do appreciate that :-)

@JasperLoy s/is/would be/. (Part of) the math world happens to be here too. I am regularly amazed about names from recent literature debuting here.

@JasperLoy probably not. This might be the best place for me.

@ccorn You look beautiful too.

@JasperLoy Aaaaargh :-) :-)

@ccorn Are you an undergrad?

@JasperLoy No. Look up my age. I'm an engineer actually.

@ccorn I don't know if everyone can see your age.

@ccorn Ah, I am old myself. Anyone past 30 is old to me.

@robjohn Everyone can see the age, but not the birthday.

@JasperLoy can you see ccorn's age in their profile?

@robjohn Yes, I can.

@JasperLoy okay. I forget what I could see before I was a mod.

and some things have changed.

Have to do a few things offline... BBL

see you later

(or sooner)

Hoo .. left a black mark on the world map :P LOL

@r9m ?

@Sawarnik pinned my location :P

I am located in Samsara.

@r9m WaT! You did reveal your location!

@Sawarnik :P not accurate though :P

I guessed that :p besides I placed myself in the city center.

but I always wanted to get on top of the butterfly roofs .. the view is supposed to be amazing .. but the security is too tight lol :P

butterfly roofs?

Oo. Wow.

Your campus is quite nice!

yesss

Greetings boys and girls!!!

Hello @Chris'ssis , I think @robjohn could potentially enjoy talking to you about fun brain bending integrals :)

$integrals!^5$

@Sawarnik that is not our campus LOL .. ours is the one like $\pi$ lurking behind that giant :P

@Chris'ssis Why do you need greet boys and girls separately?

Does anyone know the prerequisites for Differential Galois theory?

@r9m Oo, not soo nice. Wat was that though, TCS? :(

looking at the wikipedia page, I have never studied Lie groups. I learned Galois theory concurrently with group theory though and did fine.

could I pick up Lie groups along the way?

Today I did a mind-blowing thing, I have completely beaten myself ... I did this one without pen and paper ... math.stackexchange.com/questions/737311/…

If I wanna become like Ramanujan, then I need to do things in Ramanujan's style.

@Sawarnik Tata Consultancy Services

@r9m Ya, I know.

@Chris'ssis You need to do it your dreams then. Ramanujan himself said it.

I take more offense than you could imagine to that

And wow do I wish I was joking :(

@MickLH What did he say?

If I knew, it wouldn't be nearly so offensive

@MickLH You didn't see it? Ok.

@Chris'ssis I found your series on MSE!

@Julien Is it here? Where?

@Chris'ssis math.stackexchange.com/questions/128357/sum-of-arctangent

@Sawarnik Nope, didn't see it

@MickLH Ok.

@MickLH what you didn't see, can't offend you pal ... relax

@MickLH Shit list? LOL.

Wow, skull should be a mod! He has all the qualities in him.

@Julien Thanks. I didn't even know/imagine it is here.

@skullpatrol Or, if nothing offends me and I saw nothing... ?

@Chris'ssis You are welcome, I found it by chance. Robjohn again..

@MickLH Sure, that works too :D

@Sawarnik I hope you know I appear a lot more serious than I am

@Julien making use of the arguments is the natural approach ... (what incompletely cody showed)

With this powerful tool in my pocket I can produce things like Ramanujan (definitely).

brb

@Chris'ssis You are right. Yes clearly, is not cody works, look the pdf in his question. mat.utfsm.cl/scientia/archivos/vol11/Art2.pdf

C'mon guys hit me with some math

I think I have nose cancer

:O

@EnjoysMath what is 1/0?

integral inequalities ?

@EnjoysMath If you like 2D cartesian geometry and optimization, I have sth for you

k

hit me

@EnjoysMath what's a matter, can't handle my question?

Takes some space. OK, here it goes.

Sometimes you are given 2D cartesian coordinates of the vertices $P_1,\ldots,P_4$ of a quadrangle, with $P_i=(x_i,y_i)$ in finite-precision approximations.

You are then typically tasked with designing a test that checks whether those $P_i$ actually make a rectangle. Some small deviations from the rectangular shape are tolerable, but not too much.

Most simple-minded folks would check that the angle between adjacent edges is close to 90 degrees. Feeling clever, they'd rather use the normalized dot product giving the cosine of that angle, and check that its absolute value is below some error bound. (Feeling more clever still, they would rearrange the comparison so that they need no divisions and no square roots, but let us consider that being the usual level of skill in the art, and not mention it further.)

However, suppose some given quadrangle has a really large aspect ratio. Then even if its angles are close to 90 degrees each, opposing short edges could still have widely different lengths, in fact, the long edges might cross each other without that being detected either. Therefore, some more sophisticated folks would also check that opposing edges have approximately equal lengths and (as vectors from a closed path) opposing directions.

@Julien one of the questions I answered is given on page 1

But checking all this now involves at least two different tolerance thresholds, and the really smart(TM) folks only want one knob to fumble with.

annnnnd i'm back

with the proper picture even

hi again

hello skull

@meer2kat ur hot

Therefore, the really smart(TM) folks have invented the notion of a fitting rectangle. That rectangle shall have vertices $R_1,\ldots,R_4$ (understood such that $R_1$ is adjacent to $R_2$ and $R_4$, not to $R_3$) and those $R_i$ are determined such as to minimize the error square sum $S = \sum_{i=1}^4 \|P_i-R_i\|^2$.

A suitable indicator of the deviation of the original quadrangle $P_1P_2P_3P_4$ from a rectangular shape is then the ratio $S/b^2$ where $b$ is the shorter of the two side lengths of the fitting rectangle $R_1R_2R_3R_4$.

Now, one only needs to specify some tolerance level $\delta^2>0$, and any quadrangle with $S>\delta^2 b^2$ can be discarded as not being rectangular enough. Interestingly, as long as $\delta^2<1$, this can be proven to detect any quadrangle with crossing sides, even those with side lengths $1$cm vs. $1$km. Moreover, $\delta$ turns out to be an upper bound for both angular deviations as well as relative length deviations.

@robjohn Which one ? (1.4) ?

What's the goal application of the problem @ccorn?

lol thanks @enjoysmath

nice lookin yourself

ok let's marry then?

:D

Oh god damnit, she is hot

@EnjoysMath Solve the minimization problem $S$ for $R_1,\ldots,R_4$ and interpret what you get.

deal hahah

lol @micklh not really

@meer2kat I think there might be an isomorphism between our fundamental groups

oh?

:E

I thought he was just making the "no girls on the internet" joke at first, then I realized you have a picture on your profile

yes i do indeed

Wow I see all the guys are drooling over @meer2kat lol.

hey i'm a good one to drool over ;)

kidding

Well, I am probably too old to play this game.

droolin is for foolin

@ccorn what are valid transformations of the original rectangle?

mail threads, endless mail threads. i really just want to ignore my duties and go kill things in this game today