Talk:Absolute value
Fromat issue (old discussion prior to Feb 25, 2002)
I call that ugly and further, the symbols are no longer symmetric and it is harder to read for someone not accustomed to the greater than and equal sign. I can't imagine why you changed it. RoseParks
I made the major changes to this page, mainly to wikify what appeared to be HTML-based text and to make it more readable from my own esthetic perspective, so if you think there is something that doesn't work, I'd be happy to fix it, but you'll have to be more specific. I don't know what you mean by "the symbols are no longer symmetric", and I don't know what you mean by someone being "unaccustomed" to the ≥ sign. We have to express that idea somehow, and the only two reasonable ways are "≥" and ">=". But I think the former is more readable for students of mathematics, while the latter is more readable for computer geeks. I can't imagine the article being of any use at all to someone who doesn't know the basic symbols of elementary mathematics; if you think it might be useful for readers that elementary, perhaps the article could contain links to other basic articles explaining the comparison operators? Are you perhaps talking about the alignment of the blockquote? How do you think it should appear? --LDC---- I had used ≤ and ≥ to match "<" and ">." Actually, someone else took the font size out before you. And, I just put it back...:-(..RoseParks
OK. That's a very font-specific thing (on my machine the ≥s look a bit too small), and it makes the text a real pain to edit, but if you think it makes a real readability difference on your machine, and the text doesn't need to be edited much, go for it. I won't remove any further ones I see. I would hesitate to make that a standard practice for math pages here in general unless we do end up using something like TtH to do the conversions automatically so we won't have to edit all those font commands. I do think agree that esthetic details can make a big difference in the readability of math formulas (I really wish there were an easy way to vertically center the internal ||s within the larger enclosing ||s in rule 3 above), but the limitations of HTML are pretty severe, so you can't have everything you might want, and what works on one machine might not work on others. --LDC
bar notation
what's the difference between and ? It should be specified in the article. - Omegatron 18:04, Sep 26, 2004 (UTC)
- The latter notation is usually reserved to represent some kind of norm, such as in a normed linear space. Revolver 03:50, 27 Sep 2004 (UTC)
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"informal" definition in the lead
I've changed the following:
- In mathematics, the absolute value (or modulus) of a number is the difference between that number and 0. Simply speaking, it is the number without a negative sign. So, for example, 3 is the absolute value of both 3 and −3.
to:
- In mathematics, the absolute value (or modulus) of a number is its numerical value without regard to its sign. So, for example, 3 is the absolute value of both 3 and −3.
My reasons are that I find the former both confusing and misleading. For example, for the number three, "the difference between that number and 0", can be construed as either "0 - 3" or "3 - 0". And saying that "it is the number without a negative sign" leads to the misimpression that |-a| = a.
Paul August ☎ 13:46, Apr 17, 2005 (UTC)
- I think the change is good. We should mention the misimpression |-a| = a. I suspect it may not be obvious to those with little math knowledge. -- Taku 16:42, Apr 17, 2005 (UTC)
Is the seventh property ok?
Is is ok that |x|=sqrt(x^2) as it is written in the article? As far as I understand, the square root has two solutions: one that is positive and the other one that is negative (except for sqrt(0)). That's why I would like to fix the article but I'm not completely sure about it because the one who wrote it must have had some idea in mind. (Unsigned comment by User:Erast)
- Yes, the seventh property is correct. While it is true that for every non-negative real number x, there are two (provided x ≠ 0) numbers whose square equals x, the symbol " " denotes the principal square root of x, that is the non-negative real number whose square is x see: Square root. Paul August ☎ 15:46, Apr 19, 2005 (UTC)
Rewrite of article
I've just completed a major revision of this article in which I have:
- Expanded slightly the lead, better placing (I hope) the absolute value in context.
- Combined the "Definitions" and "Properties" sections into one section called "Real numbers".
- Named, organized, reformatted, and added to the properties in the "Real numbers" section.
- Moved all the content about the complex absolute value to one section called "Complex numbers", and expanded.
- Moved content pertaining to absolute value functions to its own section called "absolute value functions", and expanded.
- Created new section about absolute value in ordered rings.
- Created new section called "Distance", describing the relationship between the absolute value and distance.
- Created new section about absolute value in fields.
- Moved content about norms and vector spaces to new section called "Vector spaces", and expanded.
- Added a "References" section, and some notes.
I'd appreciate any comments/criticisms anyone might have. Thanks, Paul August ☎ 19:49, July 16, 2005 (UTC)
Wikipedia logo appears on top of article text in the following browsers: Mozilla 1.7.8 (Debian Sarge), Konqueror (Debian Sarge), Netscape 7.1 (Windows XP). --Trovatore 21:20, 16 July 2005 (UTC)
- Travatore: Can you isolate what the problem is? Paul August ☎ 21:24, July 16, 2005 (UTC)
- For the record, it looks ok to me in Safari, Firefox and IE (MacOS X). Paul August ☎ 21:31, July 16, 2005 (UTC)
- Experiments in my sandbox suggest that it's the Ent and Rf templates. Removing just the Rf's doesn't solve it, but removing both Ent and Rf does. I haven't tried removing just Ent. --Trovatore 21:42, 16 July 2005 (UTC)
- I've replaced each template with it's substitution, did that fix it? Do other articles use thes templates like Demetrius of Pharos have this problem? Paul August ☎ 21:54, July 16, 2005 (UTC)
- Didn't fix it. It must be a very strange bug--removing any 2 of the 3 Ent templates fixes the problem, but removing 1 of 3 (no matter which one) does not. --Trovatore 21:58, 16 July 2005 (UTC)
- Demetrius of Pharos looks fine. --Trovatore 21:59, 16 July 2005 (UTC)
- I've made another change, added ending div tags, does this help? I'm afraid I'm flying blind, grasping at straws and mixing my metaphors (when i'd much rather be mixing my drinks). Paul August ☎ 22:17, July 16, 2005 (UTC)
- Yes, it worked --Trovatore 22:21, 16 July 2005 (UTC)
The last change (inserting the <div>s) worked --Trovatore 22:15, 16 July 2005 (UTC)
- The older version Trovatore mentioned at Wikipedia talk:WikiProject Mathematics still works fine for me in Mozilla 1.6 and in Konqueror 3.2.2-4. Oleg Alexandrov 22:51, 16 July 2005 (UTC)