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05:00 - 20:0020:00 - 00:00

05:37
Is there a good beginner friendly probability book that is also moderately strong in developing theory? I am sick and tired of reading this statistics book, it makes me feel like a donkey, hardly any proper understanding, just lousy definitions and application, without much motivation either. I feel numb. I don't mind heavy handed analysis usage, I would rather struggle in that way than I am right now
I have taken a course on $\mathbb{R}$ till riemann integration, a course on Linear algebra (pretty computational though) and no knowledge of measures. If the book develops it as required that would be good
i have no good suggestions sorry. i have probability by Durrett, but it is not beginner friendly
 
3 hours later…
08:23
@copper.hat no worries. i have borrowed a book called "a first look at rigorous probability" written by rosenthal. appears promising
 
2 hours later…
10:11
Yeah you need something that develops Lebesgue integral
11:00
@nickbros123 Maybe Capiński and Ekkehard Kopp's Measure, Integral and Probability?
(I remember reading a few chapters from it a few years ago and it felt like a good use of time)
I've also heard the Le Gall has a good book on those topics
*that
11:18
@Khallil do they cover Lebesgue integration or at least introduce it?
11:35
Yes, both of them
(Would be very strange to encounter a book that purports to cover measure and probability without touching Lebesgue) :S
One does it in chapter 2 and the other in chapter 3
12:30
@Jakobian I'm still struggling with this idea; if we equip the co-domain with the Lebesgue sigma-algebra, not every continuous function is measurable, right? As exemplified in the link above.
@psie the thing is that no one does that and its not what being measurable means
I see
I'm repeating myself but so be it
Let $f:X\to \mathbb{R}^n$ be a function where $X$ is a measure space. Then we call $f$ measurable if its measurable with $\mathbb{R}^n$ equipped with Borel sigma-algebra
Lebesgue measurable function is a function $f:\mathbb{R}^n\to \mathbb{R}^m$ where domain is equipped with Lebesgue-measurable sets
Lebesgue measurable functions are often called measurable
@Jakobian right, this would be a Borel measurable function I guess
Borel measurable means when domain is equipped with Borel sigma-field
@psie NO
Its MEASURABLE
Function
Adjectives like "Borel" or "Lebesgue" refer only to domain
If we mean something else we have to specify what sigma-algebras we are using
In particular there is no common name for Lebesgue measurable to Lebesgue measurable type of measurable functions
When someone says "measurable", either they're dealing with abstractly chosen spaces with specified sigma-algebras, or equip codomain with Borel sigma-algebra
Any hint on this?
Ok, I see.
The type of measurable functions you link, they are the odd ones
I'm using this definition:
12:41
The definition is correct
There's a slightly more general definition
great
The codomain is equipped with Borel sigma-algebra like it should be
Nothing I didn't say already
(because you may be dealing with a function from a measurable space into another general measurable space that might not be $(\mathbb{R}^{n}, \mathcal{B}(\mathbb{R}^{n})$)
In mathematics, a measurable space or Borel space is a basic object in measure theory. It consists of a set and a σ-algebra, which defines the subsets that will be measured. == Definition == Consider a set X {\displaystyle X} and a σ-algebra F {\displaystyle {\mathcal {F}}} on X . {\displaystyle X.} Then the tuple ( X , F...
Interestingly, Wikipedia say the terms measurable space and Borel space are synonymous
(not personally a fan of that)
@copper.hat Statistics? or probability? Durrett is a probability text, isn't it?
12:47
@SoumikMukherjee Fubini or substitution
Though I guess the question is a bit unclear... he first asks for probability, then complains about the statistics text they are working out of.
I'm confused...
Do you recall the same formula from probability?
@nickbros123 Are you looking for a probability text? or a statistics text? What are you reading right now?
They are reading a statistics text that they find the text isn't formal enough
Its the kind of statistics text you'd read as an engineer probably
Nick is studying physics with intention of switching to mathematics
@Jakobian That's fine. I'll wait for them to answer the question, though.
I'm after a reference, not a general description.
12:54
@Jakobian Sorry I am not getting it, can you tell what substitution to do here?
thanks for clarifying this Jakobian, I finally grok it now I think :D It's a subtle definition...
@SoumikMukherjee $u = f(x)^p$
Something like that
you should get $\int pt^{p-1}P(X > t)dt$
well more or less. But its you that should be worrying about the details of the problem
here $f(x)$ being the density of $X$
Even if you can't directly apply substitution, I've already mentioned another way which works for sure, Fubini
Just write $f(x)$ as an integral of $y$
13:11
@XanderHenderson yeah, jakobian is right. im a phys student, but next semester ill switch to math. i am reading hogg, mckean, craig, introduction to statistics. My course, a statistics one, also follows the same book, but honestly, to read that book, and to succeed in that course, i find i have to remove my brain and become a machine. it all maps back to probability theory that i feel like im better off reading probability theory
@Jakobian Yes I am getting $\int_0^\infty py^{p-1}\Sigma_f(y)dy$
Thank you
@nickbros123 So that text is a statistics text (and, in my opinion, a perfectly reasonable undergraduate text on the topic---it is what I used when first learning stats). It is not a probability text, and only includes enough probability at the start to get you going.
The other books that folk have recommended here are probability texts, which are much less relevant if you are trying to learn stats. And yes, you do kind of have to move your brain into a different space when learning and doing statistics. It is a different field from probability.
Though if you are getting hung up on the probability, either Durrett or Ross might be useful. I think I have slight preference for Ross at the beginner level (it doesn't really expect that you come into the text with much more than basic analysis, or possibly even calculus).
13:26
I will learn stats, sure, but it feels incomplete reading that book, and I get that sort of stomach ache feeling without the concreteness. moreover, i just feel like im reading definitions and assertions and doing problems without motivations or more exploration on a certain definition/assertion.
That's fair, I suppose, but I don't think that reading a probability text is likely to help.
They are different topics.
I don't have a better stats recommendation (I don't know stats at all, really). You might try asking in chat.stackexchange.com/rooms/18/ten-fold .
@XanderHenderson Yeah. Don't be afraid of statistics, learning probability won't help you with this
well, I think, and i could be wrong here, the fundamentals like random variables, pdfs, cdfs, expectation values and so on are the overlapping topics right
@nickbros123 Probability and statistics are connected, but they are not the same.
I think of statistics as being the study of "inverse" problems.
In probability, you have a given probability distribution, and ask questions like "what kind of data will this distribution produce?"
In statistics, you have a collection of data, and ask questions like "what underlying distribution produced these data? what are the parameters of that distribution?"
It is like the connection between differentiation and integration.
So, yes, it is helpful to have an understanding of probability when learning statistics, but the "probability mindset" isn't really the right place to be for statistics. And (thanks to the central limit theorem (or Donsker, if you want to think more generally)), everything is normal (ish).
I don't consider statistics to be mathematics anymore
13:36
@XanderHenderson I see. I havent gone deep into statistics, as in, im still reading on random variables, pdfs, cdfs, transformations on discrete and continuous RVs, expectations stuff.
@nickbros123 Like I said, the book that you are reading gives a very quick overview of basic probability, since you need to have some knowledge of this before diving into stats. But that isn't the goal of the book. It is meant to be a review.
So if those chapters are causing pain, it might not hurt to pick up Ross. But I think that you are going to be better off just getting through those sections, and then seeing how the rest of the book pans out for you.
@XanderHenderson maybe its only 1 chapter, the first one titled: probability and distributions. from there on it goes onto multivariate distributions and other special distributions
and yeah, ill pick up ross, thanks.
I do have the time this semester to do both if I dare to
Don't overdo picking up Ross because you're going to start learning formal probability and you won't be learning any statistics
at least from my experience, I know its probably a bad idea
13:52
what do u gain from learning philosophy?
philosophy of science, conciousness, morality, etc
My brother studies philosophy. He gained new delusions
I guess a better question is what can you gain
clearly its not good for everybody
maybe. it can make you go mad
I don't think it can
Someone who's brain changed in that way may be influenced by philosophy but its certainly not the root issue
Philosophy in itself is not much relevant (to someone getting mad)
oh. yeah... matters like someone getting mad are complicated. it's take a lot of causes
@RyderRude That seems like a good question for a philosopher, not a mathematician.
13:57
but anyway.. what is your view on philosophy?
my view on philosophy is very simple
If everyone were like me, no one would be studying philosophy
because I'm of opinion that everyone should form their own opinions via experience
rather than studying the old ideas, I'm of opinion that they're not worth studying
this can apply to philosophy of morality and rationality, for instance
You are asking the wrong room.
philosophy of science and consciousness is more like a matter of study
maybe he's just curious about mathematicians opinions
13:59
@XanderHenderson are non math topics not allowed?
@RyderRude It isn't about what is allowed.
It is about getting a good answer.
whetever opinion on philosophy correlates somehow with mathematical knowledge, well thats another issue
oh. then i am asking here because i think you guys can give good answers too.
Of course we can. But we can also give stupid ones
14:00
there is also the philosophy of mathematics, which is about setting foundations for mathematics
this i think is a matter of study
@Jakobian i think everyone is capable of doing correct philosophy. philosophy is just a fancy name for organised thinking
@RyderRude Again, I would ask a philosopher about this before spout off.
There are various opinions on what philosophy is
this is why we say that many fields like science and math diverged from philosophy
hi
the subject is extremely general, yeah
14:02
in fact - what philosophy is, may be a question for philosophy
lol yeah
@Sahaj hello
okay what do you gain from studying math?
Integrals of the form
$$\int \frac{1}{f(x)+g(f(x))+g(x)}$$ remains difficult
@RyderRude Satisfaction.
14:03
great answer
@RyderRude knowledge and self-fulfillment
Pleasure
A better question might be "What is the point (goal) of studying mathematics?" Broadly and generally, what does humanity gain from it?
no, that would become a different question about the advacement of technology
14:05
I think what humanity gains and what does a mathematician gain are two totally different interests
yes. exactly. i wanted to ask the personal question
Personally, I work in areas which I hope have no applications---when mathematics gets applied to "real world" problems, the end result is typically a better tool for killing other people. So I don't think about that question in terms of technological advancement.
And the fact that you went there immediately kind of shows why this is a better question to ask.
what else could society gain from mathematics?
it must be the applications
What does society gain from poetry?
or is it "satisfication" for that too?
14:07
Society gains the means to further explore subjects different from mathematics
@XanderHenderson lol i thought you were going there. but note that not everyone enjoys poetry or art
Poetry is so worthless
They also gain the means to simplify and organize daily life
@RyderRude No. But would you deny that society benefits from the existence of art?
so the "satisfaction" gained by society comes down to the satisfaction gained by individuals, which my first question was about
14:08
@Sahaj You are certainly entitled to your opinion.
The benefits of mathematics to society are much more practical
@XanderHenderson i dont see how people who dont enjoy that art would beneft
The comparison of mathematics to art works if you're a mathematician. But everyone can look at art. Can everyone look at mathematics?
i think "technology" might be a strong word. but like @Jakobian says, society gains useful knowledge from math
like addition is really important even if it cant be called technology @XanderHenderson
why addition, lets just look at statistics
14:10
@XanderHenderson definitely probability
@Sahaj LOL
aka lies :P
sorry damn lies
@XanderHenderson no but really, I fail to see how poetry and even literature are useful for human species and their development. Mathematics on the other hand is much more useful and practical for development of science and technology
Bayesian probability is a really important way of rationalising
but even this is an application of math
a significant portion of math is without application, simple as
14:12
so you can either gain satisfaction or applications
is there anything else
or you can gain both
@RyderRude Its not what I'm even talking about. Organizing data is important for many reasons. It doesn't even have to be for reasons of showing to the general populi
@Jakobian If done well? Yes. I think that good mathematics can be appreciated by nearly everyone. For example, consider the work of expositors like Steven Strogatz or Keith Devlin, who have both worked to explain mathematical ideas to the non-mathematical public (and been reasonably successful at it).
Agree to disagree
I'm not even going to attempt to argue this
I'm happy to disagree. But is it necessary to follow up with such a condescending comment?
whats your issue
14:16
ummm
do you guys have a rivalry?
oh
what other subjects do you find satisfying?
I'm just blunt and Xander doesn't handle that well
@Jakobian Again, is it really necessary to be so condescening?
In particular he likes to consistently misinterpret my comments
as some kind of attempts to be condescending
14:19
Dude, if you claim that other people are misinterpreting your comments, maybe the problem is you.
Only you
my interpretation is that your comment was dismissive of Xander's PoV, but not super insulting maybe
It wasn't insulting at all honestly
I've considered that point of view and merit of it but I decided to still disagree without arguing about it
yeah
"I'm not going to even attempt" can sound bad to the person as if you are saying that they are objectively wrong
but you also said agree to disagree
14:22
maybe I should have added all that type of fluff people add in their sentences to not make it seem like I'm trying to be insulting
"I'm not going to even attempt" that's what i say the day of the exams :)
@RyderRude other than mathematics?
None
oh
math itself is vast af
everyone can look at some mathematics and there's some good exposition
most people cannot look at research-level mathematics
including most other mathematicians not in that very specific area of research
i think there's so many interesting fields. i cant sort what knowledge to gain
14:29
ah I know. I like paleontology and history of human beings
i am liking physics, math, philosophy, evolution, history among others
einstein said the last person to be able to know it all lived in the 18th century or something
I'm now of opinion that whole religion of Christianity is misinterpretation of the Bible and Jesus' teachings
are you religious?
I'm an atheist
oh you just study the history
14:32
I worship Grothendieck
I'm somewhat of a satanist myself
There's evidence in the Bible that Jesus was an apocalyptic Jew, and the apocalypse he was talking about were to happen soon after his death
is this view well held among historians?
is there any data on average age groups on math stackexchange
i think there are a lot of mis-predicted apocalypses in history
14:34
@RyderRude Biblical historians, yes
almost everyone I see seems to be some PhD with years of experience
empirically speaking, that is not true
If you look at John the Baptist, the only thing he could possibly have in relation to Jesus was that he also was an apocalyptic Jew
If you look closely in the bible, you will see that John the Baptist is talking about axe being in the tree already or something... he's referring to the apocalypse
14:38
is this the judgement day?
yes
should be that
this would mean that the prophecy was false... but religions keep getting re-interpreted whenever something is false
Well yes, I think Jesus gained influence (and was real), because of being an apocalyptic Jew, and then people kept on misinterpreting his teachings
Creating Christianity what it is today
yeah..the modern practice of religions should be unrecognisable from the original thing
lots of add-ons
preachers do learn this at the universities
they just don't preach about it
14:42
lol
religion is weird. evolutionary history is fascinating
For me its not about religion at all
religion is also very recent, at least the surviving ones
I'm interested in history of humanity
I'm an atheist, there's no reason for me to be interested in religion
yeh. religion plays a big role in society
and in shaping history
like the evolution of morality
Well it does baffle me that people interpret arguing about religion as an attack on it
especially any criticism of it
14:46
criticism is a mild form of attack tbf
but not an outright attack
That's only one meaning of what criticism is
theres also constructive criticism
I'm talking about criticism as in analysis of the Bible
The usual argument is that you either believe or you don't
that's not arguable so the discussion usually ends at that, but it doesn't exhaust convincing arguments
14:49
analysis should be independent from belief
religion historians may not believe, and their neutral analysis may contradict the religious interpretations
this leads to tension between believers and neutral historians
Most of Biblical historians are protestants from what I heard
a historian isnt going to admit someone is divine. their analysis would be based on why a human thought they were divine
this leads to blasphemy :P
blasphemy is just another word to deter you from thinking about it
The main critics of the Bible are religious people
Rare to see chat this much active at this time of the day
oh. thats unexpected
14:55
for me as an atheist it just confirmed my already existing opinion
Were you always an atheist?
atheism is confused with anti theism these days
@SoumikMukherjee No but I was a kid so I didn't understand those things and religion is forced on you at that age
which is actually something I don't like
True, most people become religious as it is forced on them from childhood
And they don't reflect on it at later stage
14:58
you said you dont do philosophy. but i gotta ask... are you a materalist or dualist (or something), regarding the universe? (or maybe you dont have an opinion)
I don't know what that means
oh
i will leave it then :P
Hard to unlearn things that are rooted deep inside
I do like Christian traditions like Christmas, I wouldn't want to unlearn it
Its my tradition, not just a religious one
Nothing wrong with festivals
15:01
not to mention they existed before Christianity came to Europe
they're pagan holidays, adapted by Christians
I think its a very good tradition
and I'm not talking about what Americans think Christmas is
a holiday for shopping at mals
Kolkata Christmas Festival, held every December in on Park Street, Kolkata, is one of the largest dedicated Christmas carnivals in India. The themed lighting starts from St Xavier's College and ends at Jawaharlal Nehru Road. This has been extended in recent years at both ends: up to the Mullick Bazar crossing on Park Street, and up to St Paul's Cathedral on Cathedral Road, an offshoot of Jawaharlal Nehru Road. Another offshoot of celebrations and lighting has been extended to Vardaan Market on Camac Street. This themed lighting is designed by artisans from the nearby town of Chandannagar. Bands...
I have never experienced actual Christmas though
Its about sitting near the table with your family, with food placed on the table and Christmas tree decorated in the room
that's what it boils down to
presents and all, that's part of it too, but not what Christmas is about for me
its about family
and good food
15:15
Yep. And the Christmas tree shines pretty in the corner of the room. Decorating it is also nice :D
 
1 hour later…
16:37
@nickbros123 Can you provide me a little clarification? I don't get what you mean by $hubbard^2$ ?
@SoumikMukherjee Can you suggest me a good book on multivariate calculus for a beginner? I am starting on that topic. I am recently asking this question for a few days now, gathering various people's opinions.
@ThomasFinley I believe it's Vector Calculus, Linear Algebra, and Differential Forms: A Unified Approach Textbook by Barbara Burke Hubbard and John H. Hubbard
(Hubbard and Hubbard)
yeah, it's just a funny way of referring to it
ah! My bad! Thanks! I know what that means now.
Luckily, I am only Ted$^1$.
@Thorgott Funny, but common. I knew exactly what was going on. It is like "Baby Rudin". If you know, you're one of the cool kids.
16:47
@TedShifrin I can pull some strings with a Tedd and Teddy...
My book got written because I tried teaching out of Hubbard$^2$ the first year.
Tough time teaching out of $d^2 = 0$
badumtssss
You want a wedgie?
@ThomasFinley The answer is obvious. Prof Shifrin's Book. You can work along with the youtube lecture series. As a bonus you can ask for clarifications from the author himself if needed.
Obvious is not necessarily optimal.
16:59
@SoumikMukherjee I don't know about that. I've heard that the author is kind of a curmudgeon, and he eats undergraduates for breakfast.
AND he hands out wedgies to nerds.
does anyone have a pirated version? :D
@SoumikMukherjee That had better be a Rickroll. If not, I will be very dissappointed.
i heard the author gave so many Fs that his school put him on triple secret probation, and he wasn't even allowed to teach certain classes unless he was under video supervision, and wheeled into lectures in one of those hannibal lecter setups
@XanderHenderson hehe
17:16
@TedShifrin Would you like some fava beans and a nice bottle of chianti?
@ThomasFinley yeah sorry about that, that wasn't really helpful 😅
17:27
@TedShifrin you're books really cool as well. For 2-3 months I was thinking (mulling on the back of my head) how to invert the Hilbert matrix, and due to a moment of serendipity from reading your book I came across the highly unobvious block matrix inversion which solved the issue
@XanderHenderson Sure :)
Yeah, you told me that before, nickbros. That's in pretty much every linear algebra book.
@TedShifrin unfortunately not in Hoffman kunze :(
That is a completely theory-oriented book.
In fact me and my friend joked on the way H&K ask that question in the very first chapter, it goes like: ".... Appears as if this matrix [the Hilbert matrix] is invertible. can you prove that?" And we concluded the right answer to that question is no xD
I don't see that blocks help for that. And, besides, does the commutation hypothesis hold?
17:33
@TedShifrin in the induction proof it helps. It was just a lot of computation
And what do u mean by commutation hypothesis?
You need $AC=CA$ or something similar.
Anyhow, there are nice conceptual ways of looking at that matrix so that invertibility is obvious. Brute force computation is not the way to go.
I don't remember the details of that computation really. And I agree, that wasn't really helpful in the grand scheme of things, but when I was reading the 1st chapter and encountered the problem, I noticed that each term was an integral of $x^n$ from $0$ to $1$, and I realised I have to wait until I learn inner products to take a jab at the problem again
Yes, that's the right approach.
Just like you can use function spaces to see easily that the Vandermonde matrix is invertible.
17:53
Consider the problem: "Use bisection search to optimize the problem
min for second degree polynomial f in given closed interval." Does that mean we find numerically solutions to f(x)=f(y)=a using bisection search and then return (x+y)/2 or is there an another approach?
Seems like a stupid exercise. I would say to look for the root(s) of the derivative, but why are we doing this with a quadratic?
Successive bisection is a well-known method for finding roots of functions.
18:33
Ah... I love swatting flies with cannons
A canon would be even better.
canon in what sense?
A canonical canon, of course.
@TedShifrin Sounds like category theory... ew....
18:38
the vast majority of chatters here seem to be interested in some sort of analysis
frank cannon, as played by william conrad in "cannon" [a quinn martin production]
@leslietownes Dat's a gud one.
maybe its a generation thing, it seems to me like the younger generation is more interested in category theory
"use bisection to find---" uh, william conrad is here and he's going to pistol-whip you until you tell him where the minimum is
jakobian: i've never been sure if this is a real thing or just an appearance that is a byproduct of a criticial mass of CT people being very online
ah.. yeah that might be true
18:44
I used to love Cannon (the TV show).
I hate the Pachebel Canon. It's almost as horrendous as Bolero.
jakobian: for example, and obviously my direct experience is way out of date, but i think of PDE as empirically a pretty large field, where a random math department is way more likely to have people conversant in PDE than they are in whatever the research frontier is in category theory, yet AFAIK there is no community of very online people doing PDE on the internet
@TedShifrin Aw... I love Bolero.
so if you're just online you might get the feeling that PDE is this tiny niche thing
But I can take or leave Pachebel's greatest (only?) hit.
It is the most monotonous piece of music ever written, except for some of John Cage.
18:48
My department was full of probability people. But a lot of them probably did PDE's
@TedShifrin Yes... but! It moves from section to section of the orchestra in interesting ways, he plays with dynamics---it is a masterclass in what an orchestra can do.
Care can suck it.
ted: without bolero and pachelbel, what would people do ice dancing to
Also, Bolero was probably the result of a particular kind of dementia.
Is ice dancing like ice fishing?
Cage is just... annoying.
18:49
jakobian: probability would be another example, without checking any data, i'd imagine that as way bigger than CT from the point of view of the number of people who actually do it
ted: it's less interesting to watch
Do they dip into the holes in the ice?
Is it "have shown" or "have showed"
"have shown".
thank you
ted: they might. i just meant that i think of canon in d etc. as music that only exists so that people can figure skate to it during the most boring parts of the olympics. maybe they also let you listen to it before they turn you into soylent green
19:04
@leslietownes You've forgotten how often it shows up at weddings.
sometimes people who get really snotty about pachelbel will turn and be like "vivaldi is so underappreciated" and i feel like you have to choose one or the other about all of those guys
@leslietownes Yes. You can't like both Vivaldi and Pachebel. It is the law.
i meant something else, that you have to concede that there are deep virtues within all of the purveyors of cheese, or reject all of them. you can't have one be "the good one"
@leslietownes Well, you're wrong. You have a choice. Vivaldi, or Pachebel. Choose.
CHOOSE NOW!
ted got really silent, he must be listening to the four seasons right now
19:10
I'm listening to Holst right now.
None of this is my proverbial cup of tea.
as long as nobody is snobby about cannon the tv show, i'm happy
Well, my favorite detective of all is Nero Wolfe, since he was a gourmet snob and had a gourmet Swiss chef.
Nick and Nora, all the way. :D
Cannon was a bit of a foodie, as I recall.
19:17
It just isn't breakfast until you've had your third martini.
He wasn't quite as heavy as Nero Wolfe (somewhere in 400-500 pounds, I think).
Is this the third martini to teach on?
@TedShifrin No, it helps you find the murderer, I think.
Well, Jim Rockford always had the obligatory car chases around Malibu.
@TedShifrin And an answering machine.
Indeed.
19:21
Man, that was a good show.
He was the antithesis of a foodie, though.
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