« first day (5303 days earlier)   

User1865345
User1865345
06:19
Someone asked this few years ago:
-17
Q: Is there any difference between heteroscedasticity and homoscedasticity?

user10619These terms confuse me. Some experts think that these terms have a contrasting meaning which is incorrect. Is there someone who can justify the interpretation.

heteroscedasticity
They are opposites. — Michael R. Chernick May 4, 2019 at 18:24
๐Ÿ™‚
@NickCox yes you are, for sure. ๐Ÿ˜‡๐Ÿ‘๐Ÿป
@StephanKolassa I think it's nothing unusual again. Just to localise the phenomenon, for instance, last of my two answers were unceremoniously basic and yet got so many upvotes just for the fact that the thread went to hnq. I am contented that those quick answers helped to shun the confusions of OP but that number of upvotes is somewhat not in congruence with the quality of the answers I gave.
Whereas there are few posts I have written in extensive detail only to receive zero or one upvote. Not that I care. I hope future readers would find those detailed posts helpful. And I would continue adding such detailed posts in the future for it consolidates my own knowledge too.
 
3 hours later…
Nick Cox
Nick Cox
09:01
@User1865345 The author of that question on *scedasticity has had a complicated history here and can still be found under another account using what I imagine is a real name. They were frequently suspended for short or longer periods, for many low quality posts that were typically naive, confused and stubborn. but never IIRC offensive.
 
2 hours later…
psie
psie
11:06
Hi there,
Hope it's ok I ask this question here. I've seen a couple of related questions on the site, but I thought maybe this question hasn't been asked so much in chat so I'd try here. I was wondering, which linear algebra as a preparation for statistics studies would you all recommend?
My situation is as follows; I have some good lecture notes in linear algebra, but they don't really serve as a reference. I mean not necessarily statistics oriented linear algebra, but I also don't mean to exclude those that are statistics oriented. I am simply looking for a good reference, a book that maybe can help make statistics oriented linear algebra much easier.
I get the impression Axler's Linear Algebra Done Right is a popular choice among mathematicians. Is this also a book that anyone of you would recommend?
User1865345
User1865345
11:37
43
A: Reference book for linear algebra applied to statistics?

user5594The "big three" that I have used/heard of are: Gentle, Matrix Algebra: Theory, Computations, and Applications in Statistics. (Amazon link). Searle, Matrix Algebra Useful for Statistics. (Amazon link). Harville, Matrix Algebra From a Statistician's Perspective. (Amazon link). I have used Gent...

3
Q: Recommendations for Linear Algebra Self Study (PhD preparation)

StatistijedThis is my first post, so I do apologize if Iโ€™ve missed something important. Iโ€™m preparing to pursue a PhD in statistics, and Iโ€™ve recently realized that my linear algebra knowledge is not โ€œup to par.โ€ The class that I took only stopped at orthogonal sub spaces, and I know thatโ€™s just not suffici...

references linear-algebra phd
Check those @psie.
There are two aspects: linear algebra and matrix analysis/computation. Depending on the course or field of study, you need to assess to what extent, you cover the materials.
I personally have read Hoffman, Kunze; Herstein; Axler; Ashraf, Siddeeque, Filippis (the Jordan canonical form treatment is extensive and detailed); Banerjee, Roy.
@NickCox I see. Yes, I noted the user seemed to be a bit stubborn and was hard to convince on otherwise straightforward facts.
 
1 hour later…
psie
psie
13:05
@User1865345 awesome, thank you. Maybe this is a tough and too broad of a question, but is the linear algebra in statistics mainly concerned with finite-dimensional vector spaces? I've heard Axler's book being criticized for being very functional analysis oriented, i.e. generalizing very quickly to infinite-dimensional spaces. Hence I am considering focusing on a text that maybe does not generalize as quickly.
User1865345
User1865345
As you progress, you will need infinite dimensional spaces. I think Axler is good and apart from the inner product chapter, Axler doesn't seem to be too functional analytic.
psie
psie
ok ๐Ÿ‘
 
1 hour later…
gung - Reinstate Monica
gung - Reinstate Monica
14:15
@NickCox, I am familiar from my time as a mod. Not being a mod is better for my mental health.
Nick Cox
Nick Cox
14:40
@gung-ReinstateMonica Indeed. I am in awe of the moderators, their sustained commitment, and their customary diplomacy and firmness faced with a small but troublesome fraction of posters ranging from awkward so-and-sos to trolls and sociopaths.
 
6 hours later…
whuber
whuber
21:04
@psie "Infinite-dimensional vector spaces" are more properly the subject of analysis. A good textbook on linear algebra will clearly indicate which theorems apply with no or simple modifications to all vector spaces and which ones are limited to finite-dimensional spaces.
psie
psie
21:45
@whuber yes indeed. The challenge is making the book choice :)

« first day (5303 days earlier)