Hi @Gortaur

hi @Rajesh

how is the day sir

I'm not a sir unfortunately. Today it's cloudy on the street and in my mind. How about you?

first three letters are enough to ping i guess

a lazy afternoon

What is your area of specialization ?

@Raj I just don't know if you're ok to be called Raj

I will be pleased

@RajeshD formal verification of probability models

hi

@qed hi

hi @QED

do you know about signal detection and estimation and the likes

no

@RajeshD me too

ok

CR bounds

basically signal estimation

ok

@Gortaur : formal verification of probability models, i guess has applications in Financial sector...am i right

@RajeshD my supervisor is more to computer science, control and sysbio. Personally I'm looking for the application in finance, you're right

@tb: if you happened to be here, I'd like to ask you for a suggestion

does it involve estimation theory ! another doubt is do you also use Time Series ?

What do people mean when they say they have a PDF?

@RajeshD what is estimation theory? time series I guess is statistical data, right? then I don't work with the latter at the moment

I always thought PDF was referring to Portable Document Format.

@AsafKaragila acronymfinder.com/PDF.html

probability density function ?

@Asaf: you've never published in journals yet?

@AsafKaragila Depends on the context (as with any acronym, of course).

Nope, not yet.

Howdy @JM.

Hey Asaf.

What's the name for a pdf file that is neither a scan nor an OCR of a scan? Just an "electronic" pdf?

@anon compiled pdf you mean?

I have never heard specific names to describe OCR or scanned PDF files.

from which you can grab the text? ))

Well, you can grab text from an OCR of a scan...

I don't think those things have specific names...

Eh, oh well.

Back when I was dealing with a crapton of documents of different provenances, our hierarchy was "scanned PDFs" and "plain PDFs"...

...and the scanned ones we classified as OCR'd and non-OCR'd.

Right, time to take a shower and head out to the university. I have to teach in slightly over an hour.

See you later folks.

@AsafKaragila clean and fresh showered teacher ) good luck with students

Yeah, it's the first lesson... I ought to give them a wrong impression :-)

Hello, has anyone seen the day the earth stood still featuring keanu reeves?

I have been looking for the scene where there are some equations from general relativitiy written

or physics or something

@Gortaur: you wanted to ask me something?

@tb yes, I was afk. are you here now?

@Gortaur: I'll finish typing up an answer, then I'll have time. Ten minutes, maybe.

@tb ok. just tell me when you'll have time

Xkcd vindicates me!

Hmm, my 13" laptop has a larger resolution than this TU monitor @Gortaur. I've connected it to my computer.

Hah @xkcd.

Okay, thanks for the reminder that I haven't checked for Munroe's latest shenanigans...

@JonasTeuwen happens

It does.

@HenningMakholm what does 'tongue awareness' mean? google translate do not enlightened this to me

Being aware of your tongue.

@Gortaur: It's an homage to this.

icic. thanks, @JM

I wonder if I should feel this feeling after reading that comics

@Gortaur: now I have time

It's not that deep a joke. Don't take it too seriously. ;)

@tb that's maybe a surprise for you that my question is adressed to you but anyway. Could you suggest any ideas how to find where the journal is indexed/abstracted if this is not stated on its webpage?

the journal I keep in my mind is quite well-known, but since my supervisor is not in that field he would like to be sure by which engines our paper would be found if the journal accepts it

Hm. The only math indexing/abstracting services I know are Zentralblatt and MathSciNet. If the journal's not there, I wouldn't know where to look.

Zentralblatt! Never heard of that one. Does it have any advantages over MathSciNet?

@Gortaur: what journal is this?

@JM journal of applied probability/advances of applied probability

@Jonas: zentralblatt-math.org/zbmath

Zentralblatt is a bit older...

It's older and freely available (but only with very limited search without university subscription).

Emphasis on the "very"... :(

MathSciNet: J. of App. Probability, [Indexed cover-to-cover; Reference List Journal] I think this should be a good sign

in ZBmath it also appears

@Gortaur: looks to be also listed here.

hm, so the idea is to pick up indexing engines which my supervisor is fond of and search for this journal there, right?

@JM thanks

Zentralblatt works pretty splendidly.

@JonasTeuwen splendidly is from German 'splendid'? or it is English word

@Gortaur You need to answer "what's the intended audience?"

Splendid is also an English word no? I might be confused.

@Gortaur "Splendid" is perfectly fine English.

It's also on jstor and project euclid, so I'd bet it is a sufficiently renowned journal to appear on all number-crunching-lists that are relevant to your professor.

@JM ok, then it's my confusion, sorry

@tb indeed, I told it him - but he was a bit aware that people from systems and control society will not find it

@JM my impression about the audience: mathematical finance (actuarial science, ruin probabilities) and queuing theory.

thank you guys, now I can proceed by myself

@Gortaur Two more things: can you slip a keyword relevant to the systems and control-people into the title? Also, putting the thing on ArXiV with links to the relevant sections would help raise awareness.

@tb 1. I think I will agree with my supervisor to do this. I am fighting quite successfully for the titles, but I'll have to write a thesis in this department, so it would be wise to fix titles a bit 2. thanks, that's maybe also a nice way to tackle it

and I finally have to make my personal webpage

Would ArXiV also be suitable to place a masters thesis (I've seen lecture notes on there, so...)?

@Jonas: Ask your advisor whether he finds it suitable. I've seen quite a few masters theses on ArXiV, often with mixed feelings. To put it bluntly: 1. Is there something original in it or is it mostly a recap of known stuff? 2. Are you sure you won't regret it in a few years? 3. Do you think it will be of interest to a few people or is it for satisfying a fancy of yours?

It should be transformed into a paper, but it contains much more detail. But the paper alone would be fine as well, I guess. If I'm not able to remove it (as you ask me if I would regret it or not) I will certainly not do it ;-).

In that case I would only put the preprint on ArXiV. If a few people ask you for the more elaborate version, you can still upload it.

And no, traces will remain

Okay, thanks.

@JonasTeuwen I think your thesis still would be foundable through search engines which support TU Delft library (when it does work, hehe)

Also you can put a link to your thesis on your home page, so people can reach it from there

@Jonas: When you withdraw a paper from ArXiV it looks like this. The text will still be available. Anyway: ask your advisor what s/he thinks.

That's true.

Okay, so that's not useful.

I'm waiting for the moment when I can use Hille's theorem on MSE to switch integrals and derivatives :-).

Hi all

Hi.

Let X be a topological Space If A is closed in Y, Y is closed in X Show that A is closed in X.

Done. Next task?

@RamanaVenkata show it for open sets first. If A is open in Y and Y is open in X then A is open in X

if A is open in Y, then A = V\cap Y for some open V. Since Y and V are both open in X, then... for the closed sets you just apply almost the same technique

That's just basically writing out the definitions, @RamanaVenkata.

Is it necessary that Y is a subspace of X?

@RamanaVenkata yes. otherwise you can just put discrete topology on Y. then any subset of Y will be open, but not necessarily open in X

Okay Thanks

guys, how can I extract bibtex key from google scholar?

done, nevermind

The BibTeX key from Google scholar is quite rudimentary.

But unlike MathSciNet it does give keys for ArXiV preprints.

@JonasTeuwen I fix it thereafter

just not used to create them from the beginning. maybe someday

Are it mathematics papers?

it's a math book

Right, MathSciNet should have a reference right?

let me check it

@Jonas so how do I download citation there?

@Gortaur Click the reference, then check in the dropdown box (select alternative format) BibTeX.

Coffee break, be back later.

tried it already - for should I do after?

@Gortaur building a bibliography?

@robjohn hi, Rob. Just adding some stuff there which is not sril there

@Gortaur Good morning :-)

@Gortaur Select the stuff, paste it in a .bib file.

Or use something like JabRef.

If you can't figure out, come by. I will show you.

@JonasTeuwen I use JabRef. I found that I had to press ' retreive ' button

Okay.

Well. That was tiresome.

@tb's lavender today, I see.

@Asaf what was tiresome?

Teach Calculus 1? :D.

@AsafKaragila so your shower was useless?

@robjohn It's the same gravatar since yesterday, no?

Being a TA.

@Srivatsan yes. hi

@Gortaur No, I didn't sweat. I'm just tired.

@Gortaur Oh, he was talking about the shower, I guess... =)

@Srivatsan Is it? I guess I just wasn't here enough to notice.

@Srivatsan I was teaching...

@Sri: haven't you figure out this question about sum of supremums?

@Srivatsan you know this guy - of course he was talking about a shower

@AsafKaragila was it an exercise session?

Sorry, I was of course kidding, @Asaf. No, @Gortaur, I couldn't and I saw some answer posted as well. Didn't read it.

I didn't talk about showers. I usually talk about cooking only during the last class.

@Srivatsan more an idea than an answer, but maybe a right idea

@Gortaur Yeah, but I overview the definitions and theorem that they see in class and just give them one or two proofs from the homework exercises.

we have a 20% chance of showers on Friday here.

@robjohn casted by Asaf? )) low quality magic: low probability of result

@Gortaur Um, ok. Let's see if its finished soon then.

@Gortaur I hope not :-)

@AsafKaragila is it indeed Calculus course or what?

Introduction to logic and set theory.

@Gor I think it's just cast, without the ed, but someone should confirm this.

@Srivatsan pinging me by 3st three letters only reminds me Al Gore )

@AsafKaragila not so bad for you, yeah? At least better than, say, optimal control of linear systems in robotics

@Gortaur Oh, do you mind? My apologies if you do.

@Srivatsan no, I don't ask you stop using it, just mentioned

Oh yeah, I don't mind the topic. It's just very tiring at the beginning. You have to keep writing full proofs and you cannot skip things like "easy" or "trivial" or "without loss of generality"...

@Gortaur Better than calculus...

@Gorta: we won't use the first three letters then :-)

@robjo - that's cool )

@robj: How about using @Gort?

robjo is cool.

@Srivatsan that was my point

I hesitate to use @Sri though. it's not a good word in Russian and I cannot omit thoughts about it each time I see it (

so I better use your whole name to ping you

@Gortaur Ah, didn't notice that I just repeated it.

@Gortaur Any hints as to what it means?

@Srivatsan oh, are you sure?

I can take it. Go ahead and spill the beans.

"Sri" is a nice word in Sanskrit, though. :)

I think I'll go watch a moovie and fall asleep on the sofa. Ciao!

@AsafKaragila watch a good one. Labirinth of Favn was nice

@Asaf Ciao!

See you Asaf. :)

@Srivatsan ok, so here you are. Sri is an imperative for 'to shit'

like 'sri faster, we should go out in a minute'

good night @Asaf

@robjo at 4 pm? )

I think it is not even 5pm in Israel?

"Imperative"? How does one hurry the colon?

@Gortaur Well it's 16:45, so if he watches a movie, it will be night by the time he finishes.

@JM I can confirm J.M.'s comment. In fact, srivats translates to son of Sri. Sri itself refers to the god(dess) of wealth and luxury.

@JM shall we stop it already now?

@Gortaur Yes. Yes, we should. :)

@Srivatsan ah, ok. I will try to force my thoughts in the right direction now. I hope I didn't offend you

@JM greasy food?

No, not at all.

@robjohn Oh Olestra... :D

@JM ok. because after the mentioning wealth and luxury this word would be really dangerous topic to discuss

@JM That works wonders, I hear :D

@JM so, to switch. when will you switch your gravatar?

I'm still torn on which to use next... :D

@Gortaur Having a problem stomaching this line of conversation? :-)

@Gortaur Yes, my parents apparently didn't know that I would've some inclination for math when they named me. =)

chat.stackexchange.com/transcript/message/2325169#2325169 chat.stackexchange.com/transcript/message/2325173#2325173

@Gortaur :-)

@Srivatsan you still can have some money from Clay Institute

@Gortaur Nah, those grapes are sour!

ok, I have to work on paper. I'd like to submit it this month, so see ya (in December, hehe)

Good luck @Gortaur.

All the best, @Gortaur

thank you, guys )

@Srivatsan yeah, I'll keep that for a while, I like it :)

@tb But I thought you didn't have control over your gravatar (aka your IP address)...

Well, it's no longer my ip-address. I made up some email-address with an associated gravatar I liked.

Wow. I just saw this question on the front page. 26 downvotes!

But with a bounty offered...

@tb I like the color.

@robjohn FWIW, I'll mention that I don't see 26 comments explaining downvotes. =)

@tb Yeah, but with a question like is 1 a prime? I don't think there will be any groundbreaking answers.

@Srivatsan That's true, but Doug doesn't seem to be complaining.

I can't read Doug...

@robjohn How do you get that font in between?

@JM did you block him?

@Srivatsan using backquotes.

No, I mean I can't read the guy...

@JM Ah :-)

Oh, ok. Thanks. Testing backquotes. @robjohn

@JM quite the illiterate, recently, aren't you? :D

@Srivatsan Take a look here

@tb Math is easier to read than people, unfortunately. *sigh*

Didier has submitted to the use of color!

I've starred that one, don't know why .. Maybe cause of the special word "JM"

+1 for the colours.

I'm bilingual illiterate. I can't speak or read in two languages.

@J.M. I notice he also uses \leqslant and \geqslant. Is this new?

I prefer \geqslant too.

We should have the possibility to make personal macros ;-).

@JonasTeuwen That's a nice idea. Things like \E and \P defined according to your preference... And also \mygeq, of course... =)

@Srivatsan Didier has always preferred the slanted versions, I've found.

@JM Um, somehow I noticed it only recently--one or two weeks ago. I didn't know of the slant variants before.

I wonder if it is common/ok to use it in papers.

@JonasTeuwen I agree. macros would shorten posting time.

@robjohn This cannot be a feature request, can it?

@Srivatsan I'd have to look and see if there is a previous request.

@robjohn you can use macros

@Srivatsan I think he started that only recently (I'm sure there are better examples).

@tb ...defined on a post by post basis, I suppose.

Yes, but it would be nice if we could store the macros somewhere.

@JonasTeuwen Put them into your bio, for example. you can comment them out using html <!-->...<-->

It would make it more difficult for newcomers who need to learn TeX by looking at the source for others' posts.

Huh, I thought he always used slanted ones. Guess I was seeing things.

@tb But then I would have to copy and paste them every time?

@HenningMakholm Actually judicious use of macros will make it easier to read the source, right?

@tb cool! do the macros just persist for one message?

@robjohn, yes they don't affect the other posts in the same thread.

@tb So only use them if you are going to use that construct more than once in a post.

"My TeX tics"... :)

@JM you have a tic when you write TeX?

@robjohn I'd say so. I usually place the declarations at the end of the first paragraph, because they produce ugly empty spaces.

@tb would that mean that the macros would only work after the first paragraph?

@JM so do mine. For a while, \mathrm{d} was a pain, but now it flows.

@robjohn To the sandbox!

@robjohn No. What he means is: if you start your answer with $\newcommand{\blah}{\mathrm{blah}}$ We will prove, this leaves an unnecessary space in the beginning.

@robjohn Yes (don't let yourself get tricked by the preview where the macros also work before they are declared!) See here for an example of a particularly ugly hack I created. I couldn't think of a better example off the top of my head.

The solution is write out (say) one paragraph and then add the macros at the end of that paragraph.

@tb I am missing the point of your example. What's the hack?

@Srivatsan: I abused a displayed math environment for sectioning my answer, using $\newcommand{mypart}[1]{\unicode{x2014;}\text{ #1 }\unicode{x2014;}}$

@tb The mypart macro?

@robjohn Yes.

@tb Ah, I thought it was a cute trick. =) Reminds of that proverb about beauty and beholder...

Man, I can't figure out anymore how I made this chain of inequalities work...

Is \unicode standard LaTeX?

@robjohn I was worried more about that really.

@robjohn No, I think it's MathJaX. It lets you insert unicode characters in displayed formulas because html and markdown formatting are turned off as soon as you are in the MathJaX environment.

Let me check

@robjohn See here for the specs

@tb In certain environments, it is available with the proper package loaded.

@robjohn: That's possible. I never felt the need of using such a thing.

@tb I have on one or two occasions, but I have worked around it.

@tb How would we normally achieve your \mypart{1} effect in LaTeX?

But XeTeX or something like that just natively supports unicode, no?

@Jonas: yes

@Srivatsan I don't know, I'd probably use something like \hfill--- #1 ---\hfill If I really needed it. But I'm sure there are packages that do that.

Thanks. If need arises, I can always ask in tex.se.

Problem here is that alignment commands are simply ignored (stripped out, rather). That's why I used the math environment.

@JonasTeuwen yes, that is one of the LaTeX environments that does with the proper package activated.

@tb at least \hfill is ignored, I know that.

Out for a while. Later.

@JM Later.

When I looked at math.stackexchange.com/questions/77790/…, my first instinct was that the first equation did not parse properly in TeX. =)

Turns out it's the good ol' colour.

Heh, 4 answers in 6 minutes.

@rob I couldn't skip it ) you guys are so funny there with your 0 votes each )))

@Gortaur Hey they were only just posted.

@Gortaur Hey, that's my line, as of right now.

I upvoted Henning, because the others seemed overly complicated or not enough information.

@robjohn my intention was to put an answer too, since there were no answers that moment. But I though that about 2-3 answers will appear while I'll be typing. So I breathed deeply and prepared to have fun )

I upvoted robjohn, because his answer is the same as mine, only in reverse :-)

@Gortaur I was writing my answer and saw two others pop up. :-(

@robjohn I hate this feeling, so I try to reduce such cases for me

@HenningMakholm what is your line?

@Gortaur "you guys are so funny there with your 0 votes each"

As usual, @Henning, you beat me, but only by 52 seconds :-)

@Henning: and you wrote more explanation about recognizing \sum x^k/k.

@HenningMakholm and what did you mean with saying that it is your line as of right now? my English does not support such phrases unfortunately ((

I use it so often, that I just assumed it.

At the time I claimed the line, my answer was the only one with upvotes.

icic

@HenningMakholm That's because I upvoted your answer to lift us from the slime :-)

@robjohn, @HenningMakholm: nice answers so +1

@Srivatsan: wth, I loved Ross's answer more than others. Why did you delete answer by Ross?

@Gortaur The deleted answer was from Ross Millikan.

@HenningMakholm there you go, showing off your new found powers :-)

@HenningMakholm thank you, I've fixed my question to Srivatsan

or just remembering ...

<insert manical laughter here>

The "about" box on the chatroom doesn't handle markups like the one for MSE.

I tried copying my about message, and it looked like the source for the other about box

@Henning: that was a quick acceptance :-) your answer was more complete, so you definitely deserved it.

@Gortaur What do you mean when you said I deleted Ross's answer?

Ok, never mind. I wish I could delete answers posted by others. That would be cool... =)

There are high schools where they do infinite series? math.stackexchange.com/questions/78219/…

That was puzzling to me, as well.

I guess they do geometric series and all related ones. And this one is related...

Oh yes, actually now I remember.

@HenningMakholm It probably depends on the high school and the class. I wouldn't have been surprised to see some of the better math students at my high school dealing with something like that.

We did all the basic series (geometric, exponential and logarithmic) in high school.

Of course, none bothers about convergence issues at that level. Just the manipulation bits.

A popular question was \sum P(n)/n! for various polynomials P.

Cool. When I was in high school, the highest-level math course got us to integrals and some simple ODEs, but no series. I did a project of the complex exponential, but was not even introduced to its power series, as far as I remember...

yawn

That was a fine nap.

@AsafKaragila You should go back to sleep. We'll wake you when we discuss what we covered about forcing in high school.

:P

It's been a while since somebody posted pretty much exactly the same answer I already posted. :)

@Mike How did you get into OR?

I'm on the same floor as the OR group in Delft, analysis and OR are both small groups.

@Jonas: so you should exploit synergies and do convex analysis.

Well, there is some guy in the OR group that does optimization using harmonic analysis!

@Jonas: After a year of algebra and a year of topology in my master's program I felt like what I was studying was abstraction for its own sake. I wanted something more applied. I didn't find numerical solution of partial differential equations interesting (which was big at Texas A&M at the time I was there for my masters), but I had always enjoyed probability, combinatorics, and algorithms. OR seemed like the logical choice.

Right, it seems like it was a good choice.

It seems like you need to be really good if you want to find a position in abstract things like algebra or (abstract) analysis. I have the next four years to also figure out how the stuff I know can be applied. :).

Once of the nice things about OR is that if I ever get tired of academia I can (hopefully) easily find a job in industry.

In fact, for the second half of my sabbatical this year I'm going to be working for a financial services firm in Seattle. I don't know a lot about the financial applications of OR (I lean toward OR theory, and my adviser worked on transportation problems), so it should be interesting.

Transportation problems as in optimal transport (Villani and so on)?