User talk:KS

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Contents 1 Dummy topic 2 Symbols not shown 3 Entering Unicode 4 Geometric/Clifford algebra 5 Uploading images? 6 Error adding new pages 7 Image uploads disabled

Dummy topic

Question about dummy topic? AUser, 01:01, 1801-01-01 (UTC)

First paragraph of reply to question.

Second paragraph of reply. KS, 02:01, 1801-01-01 (UTC)

Followup question? AUser, 01:01, 1801-01-02 (UTC)

Reply to followup. KS, 02:01, 1801-01-02 (UTC)

Symbols not shown

On the Cross_Product page, where there should be R for reals, I just see a rectangle. What might be the cause ? --Kaba 12:19, 16 Aug 2005 (EDT)

The STIX font project has not yet saved the (mathematical) world. The character used for ”reals” is Unicode U+211D [DOUBLE-STRUCK CAPITAL R], which is produced by entity codes “ℝ” and “ℝ” as well as direct use of UTF-8. We could use boldface R instead as a temporary workaround for this character, but there will be many others.

To see special characters, you need to be sure that you have suitable fonts properly installed, you need to use a capable browser (most are, I believe), and you need to have the browser properly configured to use the necessary font(s). Unfortunately, the details of doing all this depend on OS (various Windows, various Unix, various MacOS) and browser (IE, Firefox, Opera, Safari, …). Likely we’ll want to create a help page for this, but meanwhile you might find Alan Wood’s site a good place to start. At the moment, the browsers from the Mozilla Foundation, such as Firefox, offer the best support for mathematics (and also standards and security); and for these, help is available.--KS 22:09, 16 Aug 2005 (EDT)

Entering Unicode

Ken, how do you enter all those Unicode characters? Some, I can copy-paste to the pages I edit, if anyone (read: you) have used them already on another page. But this is painfull, and restricted only to the characters used before. I can display pdf-ed Unicode chars, but I do not see a way to transfer the charactes to wiki. --Pkoprowski 10:38, 21 Aug 2005 (EDT)

There are a number of ways to get special characters into a page.

1. The first, and simplest, is to use <math></math> tags and LaTeX names, like <math>\pm</math> for “±”. (But it's often incongruous and ugly: “”). I hope before long we will need nothing else because MathML rendering will be used. Meanwhile …
2. If your browser handles the edit region in Unicode, you can copy the character from anywhere you find it and paste. The easiest is elsewhere on the page, but another page or application will also work. A helpful collection of tables can be found in the fonts pages of the Mozilla MathML project.
3. Wikipedia kindly provides Javascript “insert” links below its edit region; I'm hoping we can figure out how to do that here.
4. Some characters have HTML “entity names”, such as “&plusmn;” for the plus-minus sign (“±”). A preview of the page will produce a Unicode character (“±”), which can be copied and pasted back into the source for readability. There aren’t enough of these, but they're listed here.
5. Every character is available as an HTML “numeric entity”, such as “&#x22c9;”, which is the symbol “⋉” for semidirect product. Again, this can then be copied from a preview. A helpful source listing all the characters MathML knows about (many more than pure HTML names) is provided at this W3C page.
6. Some operating systems (e.g. Windows XP) or add-on software (e.g. AllChars) provide extended keyboard entry methods for some or all of Unicode. For example, recent versions of MacOS X have “Unicode Hex Input”, where you hold down the [Option] key while typing four hex digits. Or in WordPad with recent service packs for Windows 2000 you can hold down [Alt] while typing “+” and the hex digits all on the numeric keypad. (You can't do this in the edit region, it seems.)

It occurs to me that we might make a special Help page for the FAQ listing all the characters for easy copying. --KS 12:24, 21 Aug 2005 (EDT)

Geometric/Clifford algebra

I have merged the content of the page Geometric algebra into the Clifford algebra. I believe this will be more usefull and avoids repetitions. The page you did seems more readable, so after some minor changes I copied it to be begining of the resulting (longish) entry, with the original page (after cutting off the repetitions) being the more advanced follow-up. --Pkoprowski 16:56, 21 Aug 2005 (EDT)

Ouch. I deliberately started a separate article because I see Geometric algebra and Clifford algebra as two different things, just as linear transformations and matrices are two different things. I have a great deal more to say about the geometric aspects of GA, and I suspect you could say a lot more about the algebraic aspects of Clifford algebra. Chris Doran, I think it was, convinced me the distinction was helpful. We can build geometric algebras on top of Clifford algebras in a number of different ways, with different dimensions and signatures, even when we're just interested in 3D. So if you would please put things back the way they were, I'd appreciate it. --KS 18:01, 21 Aug 2005 (EDT)

OK, I see your point. I will revert the changes later today. There should be a way to do it auto-wiki-magically, but I cannot see it on the 'history' page. --83.16.96.166 01:51, 22 Aug 2005 (EDT)

Grrr. There is something wrong with logging procedure. Again (!) it showed me (at the top of my screen) that I'm logged in but generated 'User:83.16.96.166'. I guess some caching interfers on the way. --Pkoprowski 01:54, 22 Aug 2005 (EDT)

Maybe there's a better way to revert, but I go to the history page, open the old version for editing, and save.

On your preferences page is a check box to use a browser cookie to keep you logged in. If not checked, your login times out (rather quickly), apparently for security. This strikes me as dumb design, but despite my reservations I keep the box checked. --KS 07:52, 22 Aug 2005 (EDT)

I've just undone the changes, the two topic are again separated. --Pkoprowski 11:57, 22 Aug 2005 (EDT)

Uploading images?

Looks like image uploads have been disabled -- any way I can add images to a page I just created? Kcrane 01:09, 13 June 2006 (EDT)

Error adding new pages

When trying to add new pages, I keep getting the error

  Database error
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  A database query syntax error has occurred. This may indicate a bug in the software. The last attempted database query was: 
  (SQL query hidden)
  from within function "SearchMySQL4::update". MySQL returned error "1016: Can't open file: 'searchindex.MYI' (errno: 145)    (db65a.pair.com)".

Kcrane 06:59, 13 June 2006 (EDT)

Wish I could help, but it's nothing to do with me. You'll need to contact Matt Pharr. --KS 07:50, 13 June 2006 (EDT)

Ok, thanks. Kcrane 14:31, 13 June 2006 (EDT)

Image uploads disabled

Hello, Ken. I posted about this to c.g.a. but no-one has replied. I am unable to upload an updated version of an image to my article. Has there possibly been abuse of that feature or is there some other reason? Also, there are some files that I know I have left unused that should be removed. What is the policy for this kind of maintenance? --Kaba 17:56, 19 September 2006 (EDT)

You'll need to check with Matt about the image uploads; I know of no reason it should be disabled. (Send him email.) I can remove pages for you if you give me a list of what you want deleted. --KS 14:51, 27 September 2006 (EDT)

I sent Matt email and am still waiting for the reply. The page that can be deleted is: Half_Edge_Concepts. The images that can be deleted are: Notation1.png, Notation2.png. The following are redundant redirection pages: HalfEdgeCapabilities, HalfEdgeNotation, HalfEdgeImplementation. These redirect to the corrected names of these articles (for example Half_edge_capabilities). Thanks. --Kaba 07:12, 29 September 2006 (EDT)

Done. --KS 15:35, 29 September 2006 (EDT)

Thanks. --Kaba 19:05, 1 October 2006 (EDT)