User talk:Markus Schmaus

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-- utcursch | talk to me

Contents 1 Various questions 2 Families 3 Manifold 4 "German pride" apology 5 SVG production 6 Mdash 7 Disambiguation pages 8 You utterly failed to communicate 9 WikiProject Munich

[edit] Various questions

Also a warm welcome from me. I saw that you have been contributing to some articles on mathematics, so I thought you might be interested in Wikipedia:WikiProject Mathematics which discusses Wikipedia issues specific to maths.

I do have two remarks about your edits:

• There seems to be a mistake in the article Family (mathematics), as I stated on Talk:Family (mathematics).
• I reverted your edit at Linear independence. It is true that a projective space is not a vector space, but when (a₁,...,a_n) is introduced, it is not yet seen as an element of the projective space. This only happens in the third sequence ("It makes sense to ...").

Anyway, I look forward to your future contributions. Feel free to add me any questions on my talk page, which is at User talk:Jitse Niesen. Tschüss, Jitse Niesen 04:29, 15 Jun 2005 (UTC)

Did you want to write something on my talk page? It now has an heading Families, but no text. -- Jitse Niesen 14:34, 16 Jun 2005 (UTC)

• Yes, I present enter after starting with the heading, which triggered save page. I later was interupted writing my message.

[edit] Families

Hi, we have some discussion going on, all of them in some way connected to families. Maybe it's a cultural thing. My German professor defined a basis as a family and I found lots of German sources doing the same. But I actually found hardly any English sources doing this. Generally families don't seem too popular in the English math community. Mathworld uses the curly brackets notation for families, which I find misleading for the reasons stated in my article.

Families is a formalisation of statements as "let v₁, ..., v_n be a basis" or "[a matrix A is invertible, if] the columns of A are linearly independent" (taken from invertible matrix).

It is perfectly possible to do linear algebra without using index notation, I actually prefer index free notation

∫	f
Ω

over

I like universal properties and there is no need for families when talking about a free module over a set, the corresponding basis.

But many people, especially physicists, prefer index notation. They like to talk about first, second, or third coordinates, they use matrices instead of homomorphisms. Index notation can be formulated exactly, but this requires using families.

Making index free definitions and having pages using index notation refering to those definitions leads to small inconsistencies as is the case with invertible matrix. Markus Schmaus 15:42, 16 Jun 2005 (UTC) Markus Schmaus 14:49, 17 Jun 2005 (UTC)

English mathematical texts are indeed generally less formal than text from continental Europe in that they tend to put more emphasis on readability, sometimes at the expense of rigour; at least, that is my impression. And then there is the difference between applied and pure maths, and maths generally and physics. However, I don't actually see the small inconsistency in invertible matrix that you are referring to. Is it in the phrase "the columns of A are linearly independent"? But the "columns of A" can just as well refer to the set of columns as to the family of columns. I agree that "let v₁, ..., v_n be a basis" is not precise; it should properly be written as "let {v₁, ..., v_n} be a basis".

I hope you understand that I am not following you and trying to obstruct all you do, but I was rather surprised when somebody starts using unfamiliar terminology in some of the articles on my watchlist. -- Jitse Niesen 17:10, 16 Jun 2005 (UTC)

Consider the matrix ( (1,1)^T, (1,1)^T ), it is not invertible, but the set of columns is lineraly independent, the family of columns wouldn't be. Markus Schmaus 17:22, 16 Jun 2005 (UTC)

You are absolutely right. Let me consider what the best way is to resolve this. I am still hesitant to define basis as a family, since many will not be familiar with that term. Perhaps the standard English term is sequence. However, there is a difference between family and sequence, in that a sequence is linearly ordered. -- Jitse Niesen 17:51, 16 Jun 2005 (UTC)

A sequence is a family with the natural numbers as the index set. In the old version of index (mathematics) the term indexed set was used synonymous with family. But I have never heard that term before and I didn't find many references on google. Array might be an idea, but I don't think array is a common and well defined mathematical term. Some would use vector, but as you already noticed I think it misses the point. I still think using family would be best, but I will try to make family (mathematics) easier to understand. Markus Schmaus 15:05, 17 Jun 2005 (UTC)

[edit] Manifold

As I wrote on Talk:Manifold/rewrite, I think it is best if we let it rest for a week and calm down a bit. It would take me quite some time to react on the points you and KSmrq raise with the required care and I am afraid the situation would get out of hand before, so please take a rest and work on something else. See you in a week, Jitse Niesen (talk) 22:35, 26 July 2005 (UTC)

[edit] "German pride" apology

Greetings. On the manifold/rewrite talk page I made a remark referring to German pride. It has been brought to my attention that such a remark could be offensive in the context of German culture. Please let me assure you I intended no offense, and sincerely apologize if my attempt to be friendly may have backfired. I will apologize on the page itself when it is unfrozen, but I am mortified at my blunder and did not want to wait until then to speak to you personally about this one specific issue. KSmrq 22:10, 2005 July 30 (UTC)

[edit] SVG production

Since you placed a question on my talk page, I answered there. I suspect you are not aware of that convention, so I'm letting you know on your own talk page. (The purpose of the convention is to keep the thread of conversation in one place.) KSmrq 20:58, 2005 August 7 (UTC)

Fine with me. Markus Schmaus 21:40, 7 August 2005 (UTC)

[edit] Mdash

Just to let you know that lack of spaces around mdash; is not something that should be corrected. Both ways are acceptable. Making an edit with the sole purpose of adding/removing those spaces makes more harm than good (because you effictively creating another version of the whole article, thus consuming Wikipedia storage space. Incorporating it into an edit you would make anyway is a whole other story, of course. Just a heads up.—Ëzhiki (ërinacëus amurënsis) 23:30, 1 February 2006 (UTC)

[edit] Disambiguation pages

I am aware of the WP:MOSDAB, but looking at this particular edit I can't see how my bot had violated that. My bot removed the link to continuity. I am confused, could you explicity point out the mistake.--Commander Keane 23:36, 9 February 2006 (UTC)

[edit] You utterly failed to communicate

WAS 4.250 01:31, 10 February 2006 (UTC)

[edit] WikiProject Munich

Would you be interested in helping out atWikiProject Munich? Kingjeff 21:20, 18 November 2006 (UTC)