User talk:CyrilleDunant

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Contents

[edit] Cholesky decomposition

Hello. I am a bit puzzled by your changes to Cholesky decomposition. Why do you want to write A = LLT instead of A = LL*? Indeed, if A is real then L is also real and the transpose is the same as the conjugate transpose, in which case I can see that you prefer the first expression. However, if A is complex then this is no longer true, and you have to use the conjugate transpose. Or am I missing something? -- Jitse Niesen (talk) 20:11, 14 August 2005 (UTC)

well, technically, A has to be symetric positive. so "pure" Cholesky decomposition is really "real". But a section saying the concept is extensible in \mathbb{C}, using the conjugate transpose would be good. Also -- but this is nitpicking -- this is really useful in numerics, and though you can make calculations on complex, you avoid them as much as possible for performance reasons... CyrilleDunant 05:42, 15 August 2005 (UTC)

What do you mean with "technically, A has to be symmetric positive"? Why not Hermitian and positive definite? I agree with your last comment, which is why I didn't complain when you replaced conjugate transpose with transpose in the section on solving equations. There may well be a pedagogical value in first assuming that A is real and then extending to the complex case, but it seems you have a different reason in mind. -- Jitse Niesen (talk) 11:44, 15 August 2005 (UTC)

I must confess I am seeing Cholesky decomposition from a very numerical point of view. Which means that for all practical purposes A _is_ real (and symmetric and positive defined (hmmm, doubt on the english term... I mean "all eigenvalues are strictly positive")). That it is extensible to \mathbb{C} is obvious if you have seen once in your life a complex. So if you feel that the T version is in essence wrong, well, revert. I don't care much :)
Since you seem to be knowledgable, wouldn't it work also with quaternions? CyrilleDunant 05:43, 16 August 2005 (UTC)

I'll check some books first, just to be sure. I have no idea whether it works with quaternions; I've never used those. By the way, I'm one of those rare people who do use complex numbers in numerical computations. The English term is "positive definite". -- Jitse Niesen (talk) 10:34, 16 August 2005 (UTC)

That's interesting, don't you get quite a performance hit? what do you use them for ? My "specialty" is FEM for microstructures, and I'm always happy to learn new efficient techniques...

I'm solving ODEs with a parameter which takes complex values (in particular, I'm not using the Cholesky decomposition). Of course it's more expensive to use complex numbers instead of reals, and as you say, you try to avoid them, but if the problem has complex variables in it, you have to use complex arithmetic.

I did mention complex numbers again in the Cholesky decomposition article, but the stress is still on real matrices. I am wondering though whether the Cholesky decomposition is used outside numerical analysis. -- Jitse Niesen (talk) 17:16, 17 August 2005 (UTC)

I like the latest revision. I think it really makes sense this way.

[edit] Eurofighter

Thanks for catching that edit. I'm sure the person has a genuine objection but in that case I can't understand why they wouldn't create an account and discuss it! It's not perfect, but as I said in the edit summary they are reputable sources. Thanks again. Mark83 15:43, 23 February 2006 (UTC)

Also, it is clearly stated that the numbers are somewhat speculative. So the current setup seemed to me accurate and honest. So I reverted :) CyrilleDunant 16:12, 23 February 2006 (UTC)
BAE released there first formal report today since the deal (2005 Preliminary Report) and it says:
"It is... intended that Typhoon aircraft will replace Tornado Air Defence Variant aircraft and other aircraft in service with the Royal Saudi Air Force. The details of these arrangements are confidential."
So I think the current format is the best we're going to get for a while! Thanks again. Mark83 23:40, 23 February 2006 (UTC)

[edit] US/British English - Airbus A400M

What on earth are you doing changing Boeing Integrated Defense Systems to Boeing Integrated Defence Systems? It is wrong in every way. Primarily of course because the first article exists and the second does not! Not a very productive edit in that sense. Also it is a company registered in the United States, so you cant just change it to meet your preferences, they could register as Boeing Integrated Defennnnnnnnse Systems and we would still be obliged to link to it. Mark83 11:41, 19 June 2006 (UTC)

Ooops sorry, knee-jerk reaction -- actually, I wondered. Should have checked...:)

[edit] Mediation

The announced mediation, concerning the Charlemagne article, will take place soon, you are invited to participate. See: Wikipedia:Requests for mediation

Rex 18:24, 7 July 2006 (UTC)

[edit] Thanks

... for your kind words on my talk page, says Str1977 (smile back) 13:51, 1 August 2006 (UTC)

[edit] Block

You have been blocked from editing for personal attacks and removing warnings for a duration of 24 hours#. To contest this block, please reply here on your talk page by adding the text {{unblock}} along with the reason you believe the block is unjustified, or email the blocking administrator or any administrator from this list.Will (Take me down to the Paradise City) 14:52, 1 August 2006 (UTC)

Will unblocked you after discussion here. Cheers. AnnH ♫ 18:03, 1 August 2006 (UTC)

(Personal attack removed)


[edit] Question

I saw some of your edits on other wikipedia pages. Just curious, what country are you from? Wacki 13:51, 6 January 2007 (UTC)

  • "I am from Europe, and yourself ? CyrilleDunant 22:48, 6 January 2007 (UTC)" I'm from the US. But seriously, what country (not continent) are you from? Wacki 19:52, 7 January 2007 (UTC)

[edit] Mayo

Yeah, you're right about the "properly" being POV, at least in one sense of its use. I was thinking more along the lines of it meaning "suitably" or "correctly" but now that you've changed it there's no question but that your version is better. In any case, homemade mayo is *great*! Bon appetit! Hayford Peirce 18:34, 25 January 2007 (UTC)

[edit] Franz Liszt's article

Hi there, just wanted to say that was the correct flag for the Austrian Empire that you added, and my comment referred to the previous edit. I still want to keep it changed though, because many other people born in the Hungarian part of the Empire at that time are described as being born in Hungary, rather than the Empire, See Bela Bartok for example. Thanks for contributing to the article though. If Liszt or the article is of interest to you I'd like to know your opinion about the debates at the moment. If you were just doing a bit of maintanance that's fine too ;). All the best, M A Mason 18:37, 5 April 2007 (UTC)

[edit] Veganism

Regarding the Crown Shakur case, I have edited the additions made to the Veganism article to hopefully provide a more NPOV. Madeleine 16:20, 22 May 2007 (UTC)

Yeah, it's a funny thing to be comparing. I don't mean to defend any POV in the article and I do think referenced nutritional concerns are a legitimate issue to address. Both this and the vegetarianism article attract all sorts of claims and POV statements from both sides, it's hard to keep it all neutral but demanding references helps some. Madeleine 17:23, 22 May 2007 (UTC)

[edit] Article Tags

Without addressing whether or not the Veganism is POV or Misleading, it is considered bad form to remove another editor's template on an article, provided that editor is still a registered wiki editor and is available to remove the tag themselves.

In general, template tags are based on personal opinion, whether that opinion accurately reflects the facts or not is unimportant. If you disagree with a template, and cannot reach a compromise or solution with the other editor, there are a number of other methods which you can pursue for dispute resolution.

Revert warring will generally only make matters worse and ultimately end up with the article protected or with one or more editors being blocked.

If I can be of any assistance, please let me know.

Peace in God. Lsi john 20:10, 4 June 2007 (UTC)

[edit] September 2007

Welcome to Wikipedia. Everyone is welcome to contribute constructively to the encyclopedia. However, we must insist that you assume good faith while interacting with other editors, which you did not on Eurofighter Typhoon. Take a look at the welcome page to learn more about contributing to this encyclopedia. Thank you. KTC 04:17, 2 September 2007 (UTC)

[edit] Lift controversy

Rather than edit war over the IP's additions (malformed as they are), would you mind joining the discussion on the talk page that I'm trying to get started on the subject? Thanks. AKRadeckiSpeaketh 17:18, 29 October 2007 (UTC)


[edit] Speedy deletion of The Steam House

A tag has been placed on The Steam House requesting that it be speedily deleted from Wikipedia. This has been done under section A1 of the criteria for speedy deletion, because it is a very short article providing little or no context to the reader. Please see Wikipedia:Stub for our minimum information standards for short articles. Also please note that articles must be on notable subjects and should provide references to reliable sources that verify their content.

If you think that this notice was placed here in error, you may contest the deletion by adding {{hangon}} to the top of the article (just below the existing speedy deletion or "db" tag), coupled with adding a note on the article's talk page explaining your position, but be aware that once tagged for speedy deletion, if the article meets the criterion it may be deleted without delay. Please do not remove the speedy deletion tag yourself, but don't hesitate to add information to the article that would would render it more in conformance with Wikipedia's policies and guidelines. Hammer1980·talk 13:51, 18 November 2007 (UTC)

I fully understand your logic behind it, but there simply seems to be little information. The article needs more content and references. I cannot see a problem regarding notability. Hammer1980·talk 14:02, 18 November 2007 (UTC)

[edit] Controversy surrounding human embryonic stem cell research

Actually you have a valid point. You didn't undo my name section change, which is the part that was under discussion.

The rest I added as well as doing the name change which could be construed as an interruption to the equilibrium of the article. However the main point (but not the only one) that needs to made in this section is that not all stem cell research carries with it the inherent moral objections that are caused by the destruction of an embryo in embryonic stem cell research. I feel that the information I have added to the section fits well with the section and gives a reader a better understanding of the productiveness of embryonic stem cell research VS adult stem cell research. I am open to changing the wording if you are open to discussion of the changes. --Logiboy123 02:57, 3 December 2007 (UTC)