text:
Talk:William Walton

untitled
I believe he also wrote a set of five short guitar pieces called "bagatelles"(dedicated to Julian Bream?) I heard them back in 1993 in a concert during my first visit to London, and just a few days ago over the BBC, too. I believe he orchestrated them (as the Varii Capricii (sp??) poss.) later on as well. Very few of the composer pages here aim for an exhaustive worklist, though - perhaps more should, if not exhaustive, at least more complete! Schissel : bowl listen 16:18, Apr 26, 2005 (UTC)

Wikilinks
I recently added some wikilinks that ended up getting changed around a bit, so I changed some of them back. My feeling is that the disambiguation term (musical composition) or (opera) should be used in cases where a given title might apply to multiple things outside of music. For example, Crown Imperial (disambiguation) links to Crown Imperial (musical composition), because a Crown Imperial is also a type of car. However in cases where the title would be something in the realm of music, such as Symphony No. 1, the disambiguation term (Walton) should be used, because there may be several articles about first symphonies, all of which are musical compositions. The idea is that the term should be used thats most appropriate for what the other pages that need to be disambiguated from are. I also don't think the disambiguation term is needed for Orb and Sceptre, as there is not an article there already, so the disambiguation is not needed until other terms are added to the encyclopedia. Also, I don't really think this article is a stub, there's a little meat to it, if not a lot. If there are any questions, let me know. Ëvilphoenix Burn! 18:16, 12 December 2005 (UTC)
 * I strongly disagree. The purpose of disambiguation is to disambiguate.  To take one of the examples, Crown Imperial (musical composition) could potentially be another disambiguation page, whereas Crown Imperial (Walton) is unquestionably unambiguous.  I have more sympathy with (opera) as a disambiguation qualifier, but even then Troilus and Cressida (Walton) seems to me more specific and unambiguous than Troilus and Cressida (opera).  --RobertG ♬ talk 11:35, 14 December 2005 (UTC)

 * I don't think we should go for specificity though, I think we need to evaluate disambiguation based on what disambiguates something at the highest level, not the lowest. Crown Imperial is a term that applies to things in a broader sense than just music, so the disambiguation should seperate it out based on what makes them distinct within that level, so in this case you have Crown Imperial (automobile) and Crown Imperial (musical composition), whereas things that apply mainly to music, such as Symphony No. 1, which there will be several of, should disambiguate based on what will distinguish them within the world of music, which would be composer names. Disambiguation should be as simple as possible, not as specific is posssible.

 * To give an example, say somebody writes a play called Bob and Bill. So we have Bob and Bill. Now let's say someone opens a Fast food chain called Bob and Bill, so we'd have Bob and Bill (restaurant). Now if Philip Glass adapts that play into an opera, we'd then have Bob and Bill (play) and Bob and Bill (opera). Now let's say 100 years later, some composer named Svengardt decides he wants to write an operatic version of Bob and Bill, so then we would have Bob and Bill (Glass opera) and Bob and Bill (Svengardt opera). But what if, 100 years later, there's no restaurant anymore and no one produces the play anymore, but we still have the operas? Then Bob and Bill could be Bob and Bill (Glass) and Bob and Bill (Svengardt), because Bob and Bill of itself implies an opera. However if you also have a play and a restaurant chain to disambiguate with, you need to provide the (opera) distinction. Do you follow my meaning at all? We shouldn't disambiguate unless we need to disambiguate, and when we do, we need to evaluate how specific the disambiguation needs to be, and in my mind, it should be more general before it gets more specific. Crown Imperial (Walton) might be more specific, but unless you happen to know who Walton is, and that he wrote a piece called Crown Imperial, you might not know what Walton is referring to, whereas if you see Crown Imperial (musical composition), you at least know youre looking at a musical piece. Ëvilphoenix Burn! 17:50, 14 December 2005 (UTC)

 * I do not feel as strongly about this as you do, obviously! I would totally agree with you if we were forbidden to explain anything on disambiguation pages or to have any content in articles.  The introduction to the article would be, however, "Crown Imperial is an orchestral march by the English composer William Walton written for the coronation of King George VI in 1937," so anyone coming to the article immediately finds out who Walton was and that it's a musical composition; the only Wikipedia links which aren't explained are the category links, and the category does the explanation.  In fact, that's quite a good introduction, I'll post it as a stub rather than waste it here (I'll even go with your disambiguation, although it still looks odd to me).  --RobertG ♬ talk 10:51, 15 December 2005 (UTC)
 * That is a good introduction, I was thinking "I'm totally stealing that" before I got to the part where you'd actually started the article. Thanks, that filled in a red link for me on an article I'm trying to clear red links from. You make a good point on that we can explain things on disambiguation pages and in article content. For some reason I'm still feeling the page title itself though needs to get as much mileage as it can, regardless of the article content. What would really be nice would be to get some more opinions, as right now it's just been you and me discussing it. Thanks again for your work, and nice intro. Ëvilphoenix Burn! 16:30, 15 December 2005 (UTC)

Image
Aaaar, mateys! For whatever reasons, there is no current image of Walton. Oddly enough, the image labeled William_Walton.jpg is of William Wilton, and appears at the article on William Wilton. Did Walton's image get bumped for this wrongly named image? Signinstranger 17:04, 19 September 2006 (UTC)

Composer project review
I've reviewed this article for the Composers project. You can read it on the Comments page. If you have any questions, feel free to comment there, here, or on my talk page. --  Magic ♪piano 17:40, 13 November 2008 (UTC)

Hindemith photo
I added the image of Hindemith. See if the image experts are happy with it. -- Ssilvers (talk) 01:25, 16 October 2010 (UTC)

Introduction: Best Known Works
I would suggest that the introduction be edited to include British coronation works – 'Orb and Sceptre' and the 'Crown Imperial' coronation marches are more well-known than the examples given. Surely his Viola Concerto is also, equally famous. —Preceding unsigned comment added by 94.195.191.50 (talk) 16:49, 2 May 2011 (UTC)

Infobox
The article needs one in spite of the consensus reached among the small percentage of total Wikipedias who frequent the Composer wikiproject. Night Ranger (talk) 00:22, 29 March 2012 (UTC)
 * This has been very thoroughly discussed, and reviewed and confirmed, already. Tim riley (talk) 09:24, 29 March 2012 (UTC)
 * Yep but they're wrong. Night Ranger (talk) 13:54, 31 March 2012 (UTC)
 * Totally agree with Night Ranger; he's right and the rest of the world is out of sync. Eisfbnore  (下さいて話し) 14:29, 31 March 2012 (UTC)
 * What's funny is how 4 or 5 people on a Wikiproject consider themselves the entirety of the Wikipedia community, or in this case, the entire world. Night Ranger (talk) 02:40, 1 April 2012 (UTC)

Belshazzar's Feast
An anonymous editor changed "cantata" to "oratorio" in the text. I have changed it back again. The work has from the outset been categorised as a cantata: see Howes Frank "The Leeds Festival", The Musical Times, Vol. 72, No. 1065 (November 1931), pp. 991–992 ; Latham, Alison (ed). "Belshazzar's Feast", The Oxford Companion to Music. ; and Kennedy, Michael, "Belshazzar's Feast", The Oxford Dictionary of Music, 2nd ed. . Tim riley (talk) 10:29, 9 May 2012 (UTC)

All works of Walton released on CD? Hardly
It's common for people to take mention of a "complete works edition" at face value, but as usual Chandos's marketing is a bold faced lie. The source cited,, even contradicts itself -- if "complete works of Sir William are available on Chandos Records." then how could "the last major work of Sir William’s to be recorded", "be released next year"? (especially telling is that said 'complete works' were done by 1996 ). But more importantly, there are a number of works that HAVEN'T been recorded, or at least released on CD as claimed:, , , , , and for starters. Not to mention, the ONLY complete version of any of his film scores actually released away from the film itself was, ironically, Battle of Britain -- everything else has been an arrangement by someone else. Now MAYBE this could all be construed as WP:SYNTH (plus WilliamWalton.net is gone and the Archive.org archives are from 2010 with some of the pages needed to go back to 2008), but I certainly didn't remove the sentence 'in error'. ♫ Melodia Chaconne ♫ (talk) 14:21, 15 May 2012 (UTC)
 * I really don't know what to do for the best here. I understand what you are saying about the fanfare etc, and however reliable a "reliable source" actually is or isn't one wouldn't want to perpetuate misinformation. I suppose one could say something like "all but a handful of minor works". What think you? Tim riley (talk) 14:34, 15 May 2012 (UTC)
 * 'The majority' seems like it'd be a perfect compromise. ♫ Melodia Chaconne ♫ (talk) 15:22, 15 May 2012 (UTC)
 * Can I persuade you that "almost all" wouldn't be stretching it? Tim riley (talk) 15:52, 15 May 2012 (UTC)
 * Fwiw, "almost all" was my thought too. —MistyMorn (talk) 16:13, 15 May 2012 (UTC)
 * That works. Done (with a couple other fixes too). ♫ Melodia Chaconne ♫ (talk) 18:14, 15 May 2012 (UTC)
 * Thanks to Melodia and MistyMorn for a brisk resolution without bloodshed. Tim riley (talk) 18:47, 15 May 2012 (UTC)

US Premiere
Under "1930s" it is stated that Eugene Ormandy and the Philadelphia Orchestra gave the US Premiere of Walton's First Symphony. In his programme note for a performance of the work given in 2005 by the National Symphony Orchestra under Leonard Slatkin, Richard Freed stated that the US Premiere was given by Sir Hamilton Harty and the Chicago Symphony on 23 January 1936. (See the full text on-line in the Kennedy-Center org website.) Can the date of the Ormandy performance be verified, so as to clarify who was in fact the first in the US to conduct the work's premiere there? Philipson55 (talk) 14:07, 26 February 2013 (UTC)
 * I can get access to the archives of The New York Times at the British Library, and will check this tomorrow. Thank you for raising it. Tim riley (talk) 14:50, 26 February 2013 (UTC)
 * The note at the Kennedy centre's site is spot-on. The reference in The New York Times headline of 17 October 1936 to the work as "new here" referred only to Philadelphia, and not to the USA as a whole. The NYT's archive has a brief article dated 20 January 1936 (p. 22) that confirms that Harty and the Chicago SO gave the American premiere. Thank you so much for spotting this, which I shall correct forthwith. Tim riley (talk) 14:02, 27 February 2013 (UTC)
 * Thanks for doing the research. Although it's probably not relevant to the article, a one-time employee of the local Chicago radio station has related that because the reviews of the Walton US Premiere were so "savagely antagonistic," Harty decided against playing it again for the remaining three scheduled performances that followed the first one, and substituted Dvorak's 'New World' Symphony instead! Philipson55 (talk) 15:03, 27 February 2013 (UTC)
 * Good grief! Another clanger narrowly averted. One of the NYT cuttings mentioned that Harty was going to do the Symph three times, and I toyed with the idea of mentioning this in the article. If he ducked out of giving the two later performances it's just as well I refrained. Put not your trust in press cuttings! Tim riley (talk) 15:20, 27 February 2013 (UTC)

Persistent attempts to WP:OVERLINK
An editor keeps inserting multiple links to the same articles. See the Manual of Style which states: "Generally, a link should appear only once in an article, but if helpful for readers, links may be repeated in infoboxes, tables, image captions, footnotes, and at the first occurrence after the lead." Sound advice, and I am reverting accordingly, bringing the article back into line with other composer FAs. Tim riley (talk) 16:10, 27 November 2013 (UTC)

Notes and references
It is getting on for five years since I took this article through FAC, and looking at it again I think it could do with a little refining to bring it into line with more recent composer Life-and-Works articles. Would anyone object to my separating explanatory footnotes from the general citations, as in more recent FAs such as this one?  Tim riley  talk    21:15, 13 March 2015 (UTC)

 * While I certainly have no objection, it is my belief that explanatory footnotes should seldom if ever be necessary in a well-written biographical article. Perhaps you can point to an example here of an explanatory note that both contains essential information and at the same time cannot reasonably be incorporated smoothly into the main article text.—Jerome Kohl (talk) 21:39, 13 March 2015 (UTC)

 * Sounds like a reasonable improvement to an excellent article. Some side items of interest and detailed explanations are appropriate for footnotes, and separating the references makes it easier to skim or read them as desired. Reify-tech (talk) 21:44, 13 March 2015 (UTC)

 * Jerome, You are not alone in your doubts about footnotes (Noël Coward said that having to read footnotes is like having to go downstairs to answer the door when one is in the middle of making love) but others – and I am relieved to see from Reify-tech's comment that I am not alone – feel that there is a place for interesting, relevant but not core information that readers can look at or not, as they wish. Examples in this article are the existing notes 15, 16, 22, 34, 42, 83 and several others, plus a recent interesting but not core addition about a godson. I'm not proposing to add a lot of extra explanatory footnotes, but chiefly to separate them from the citations: a section, in short, of "You may be interested that…" and then a section of just "This is where we got the information". Most composer FAs have this dual form of noting, and I am seeking to bring Walton's article into line. –   Tim riley  talk    22:06, 13 March 2015 (UTC)
 * There being no votes to the contrary, I'll put this on my to-do list.  Tim riley  talk    19:03, 24 March 2015 (UTC)
 * And now done.  Tim riley  talk    12:00, 4 April 2015 (UTC)

Assessment comment
Substituted at 10:43, 30 April 2016 (UTC)

Hidden comments
The problem with hidden comments along the lines of "Don't add an infobox because a WikiProject doesn't like them" is that it has a chilling effect on editors who don't understand that Wikiprojects have no standing to demand that an infobox may not be added. The decision on having an infobox or not is a matter for consensus on each article, and that is policy. If there has already been a discussion on a particular article, and a consensus reached not to have an infobox, then it is helpful to have an html comment drawing the editor's attention to that (possibly archived) discussion, and I'd be very much in favour of maintaining such notes. It is not acceptable to have a note which effectively prevents any consensus from being discussed, as if the matter were already settled by fiat of a single editor or Wikiproject. We build this encyclopedia by allowing people to edit, not forbidding it for no good reason.

 * First we were told that failure to have a hidden comment made it hard for editors to know not to add an infobox. Now you say that the hidden comment has a "chilling effect."  The fact is that you just want to have a pile of code at the top of every article containing redundant infobox information, even in these arts biographies, usually riddled with errors and always emphasizing unimportant factoids at the expense key information. -- Ssilvers (talk) 19:55, 30 July 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on William Walton. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20071004023736/http://www.gresham.ac.uk/event.asp?PageId=45&EventId=698 to http://www.gresham.ac.uk/event.asp?PageId=45&EventId=698

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 23:14, 20 May 2017 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 3 external links on William Walton. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20150403002843/http://www.waltontrust.org/williamwalton/ to http://www.waltontrust.org/williamwalton/
 * Added archive https://web.archive.org/web/20120503063032/http://www.waltontrust.org/williamwalton/ to http://www.waltontrust.org/williamwalton
 * Added archive https://web.archive.org/web/20150403002843/http://www.waltontrust.org/williamwalton/ to http://www.waltontrust.org/williamwalton/

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 08:20, 30 September 2017 (UTC)

Walton formed friendships with younger composers including Hans Werner Henze and Malcolm Arnold, but although he admired their work, he did not influence their compositional styles

It doesn;t make much sense. Perhaps ...but although they admired his work, he did not influence their compositional styles, is the right expression ! — Preceding unsigned comment added by 94.66.216.88 (talk) 15:41, 14 February 2018 (UTC)

Basil Allchin
Basil was an influence on Walton's early musical career and his first piano teacher Walton's great fortune at Oxford was that the music staff with whom he came into contact were open-minded and did not discourage individuality. There was no beating him into conformity. One of his first teachers at Christ Church was the assistant organist Basil Allchin who gave him piano lessons. (He was never to become an accomplished pianist – Alan Frank, of Oxford University Press, went so far as saying that he played 'excruciatingly badly', and he was to write very little for that instrument - but an early surviving manuscript is of an 89-bar Valse in C minor dated 2 February 1917.) Walton would sometimes show Allchin reams of manuscript paper covered with notes, mostly cast in the form of elaborate motets for double choir with unor- thodox part writing. Beyond pointing out the unorthodoxy of these youthful efforts, Allchin to his credit was not discouraging. Cmadavis (talk) 22:29, 25 December 2022 (UTC)
 * Allchin receives a single passing mention in Kennedy's 350-page biography of Walton, a single one-off mention in Stephen Lloyd's 332-page biography, and an even shorter single mention in Neil Tierney's 310-page biography, and is not mentioned at all in Stuart Cragg's book about the composer. Allchin was assistant to Henry Ley, who is mentioned more extensively and might possibly be worth a sentence in the article, but in an encyclopaedia article of a few thousand words we must concentrate on the important facts. The fact that Ley's assistant taught Walton to play the piano badly and did not discourage him from composing does not seem to me among the important facts. But if others disagree with me we can make the proposed addition. Views, colleagues? –  Tim riley  talk   09:26, 26 December 2022 (UTC)
 * Because I am such a William Walton 'fanboy' (note my Wikipedia handle!) I might tend to support any additional information for its own sake. But necessarily putting aside that non-neutral POV, I agree with Tim riley that this information is not notable enough in an encyclopaedia article of limited length. Walton22 (talk) 23:12, 26 February 2023 (UTC)
 * A further attempt has been made to add mention of Allchin, falsely claiming that it is cited in the ODNB article (which it isn't, nor would one expect so trivial a detail to be).  Tim riley  talk   12:06, 29 December 2023 (UTC)

title: Talk:William Walton


text:
Category:Tournament systems

This is a category of various competition systems.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Category:Tournament systems


text:
LGBT rights in Liechtenstein

The rights of lesbian, gay, bisexual, and transgender (LGBT) people in Liechtenstein have developed significantly over time. Same-sex sexual activity has been legal since 1989, with an equal age of consent since 2001. Same-sex couples have had access to registered partnerships since 2011, and discrimination on the basis of sexual orientation has been outlawed in some areas since 2016.

On 8 March 2024, the Liechtenstein government passed a bill by a vote of 24-1 regarding same-sex marriage rights on its first reading, with the legislation expected to go into effect on 1 January 2025. The second/final reading took place on 16 May 2024, on the bill, and the parliament again voted in favor of the same-sex marriage, with 24 of the 25 MPs supporting it.

Law regarding same-sex sexual activity
Same-sex sexual activity was legalized in 1989 by the removal of Sections 129 and 130 of the Criminal Code, though the age of consent was not equalized until 2001. The Penal Code was revised in December 2000 to remove all discrimination against same-sex sexual activity, taking effect in 2001. The age of consent is 14, regardless of gender and sexual orientation.

Recognition of same-sex marriage
In 2001, the Free List, one of the three political parties in the country, began working on a draft for a same-sex partnership law. The paper was accepted by the Landtag and given to the Liechtenstein Government. The proposed registered partnership bill was rejected by the Parliament in summer 2003. A new proposal by the Free List was adopted by the Landtag with a majority of 19 votes to 6 on 24 October 2007. Justice Minister Aurelia Frick presented the draft of the registered partnership bill in April 2010. On 23 November, the government approved the final version of the bill. On 16 December 2010, it was approved by the Landtag in the first reading. It passed its second reading on 16 March and was published on 21 March 2011. A group Vox Populi announced its intention to force a referendum on the matter. According to the Constitution, the organization had 30 days to collect at least 1,000 signatures. A referendum was held on 17 and 19 June 2011 and 68.8% of voters approved the law, which then went into effect on 1 September 2011.

According to a report approved by the Liechtenstein government in October 2022, the current partnership law uses "gender-equitable formulations" in its general clauses and legal definitions, implying that both same-sex and opposite-sex couples can enter into registered partnerships under the current law.

Since 1 January 2017, registered partners have been allowed to have a common "name" as equivalent to a "family name" for married couples.

In 2018, a gay couple filed suit in court, arguing that the same-sex marriage ban is in violation of the European Convention on Human Rights and the Constitution of Liechtenstein. Although a court of first instance initially ruled for the couple, the State Court (StGH) ruled in September 2019 that banning same-sex marriage is not unconstitutional. However, the court concluded that several provisions of the 2011 partnership law were discriminatory, notably its provisions prohibiting civil partners from adopting their stepchildren (so-called stepchild adoption).

On 21 September 2022, a motion calling on the government to introduce a bill legalizing same-sex marriage was submitted to the Landtag by 15 out of the 25 sitting members. The motion was discussed in the plenary session on 2 November 2022, and was passed by a 23–2 vote.

On 11 July 2023, the government adopted a consultation report regarding proposed changes to three existing laws as part of the motion's implementation: the Marriage Act, the Partnership Act, and the Personal and Company Act. A consultation period ended on 10 October 2023. In August 2023, Prime Minister Daniel Risch said that the legalization of same-sex marriage "should be coming very soon". On 6 February 2024, the government adopted the results of the consultation report along with the proposal regarding the amendment of the three aforementioned laws. Under the proposal, no new registered partnerships would be established in Liechtenstein, although existing ones would continue to be recognised and could be converted into marriage via a simple procedure. The bill passed its first reading on 8 March 2024 with 24 votes in favor and one against.

 * a. Part of the VU-FBP Coalition under Prime Minister Daniel Risch.
 * b. Served as a substitute deputy for Peter Frick throughout the plenary legislative session.

A final vote on the legislation took place on 16 May, where the bill passed 24–1. Prior to the scheduling of the final vote, it was decided that no changes would be made towards the proposed legislation and that no referendum would be taken against it by the state parliament. The legislation received royal assent on 9 July 2024  and is scheduled to take effect on 1 January 2025.

Adoption and parenting
On 1 January 2016, during his annual New Year's Day interview, Prince Hans-Adam II announced his opposition to allowing same-sex couples to adopt children.

In September 2019, the State Court ordered the Liechtenstein Government to look into the legalisation of stepchild adoption for civil partners. On 15 June 2021, the State Court of Liechtenstein ruled that registered partners should have the right to adopt, and invalidated the sections of the 2011 partnership law which had forbidden such adoptions. It gave Parliament one year to rectify the issue. Following the court decision, the government drafted a bill granting same-sex couples the right to adopt their stepchildren (i.e. stepchild adoption), which was passed on 6 May 2022. On that same day, Parliament narrowly rejected an amendment that would have excluded same-sex couples from joint adoption and procedures for reproductive medicine for those in registered partnerships.

After a consultation period lasting from 6 July to 30 September 2022, the government passed a motion on full adoption equality for same-sex couples on 31 October 2022. The proposal was discussed in its 1st reading in the Landtag on 2 December 2022 and was passed in a 22 to 3 vote.

 * a. Part of the VU-FBP Coalition under Prime Minister Daniel Risch.
 * b. Served as a substitute deputy for Bettina Petzold-Mähr around the time of the debate & vote.

On 2 March 2023, the proposal was discussed and passed in its 2nd reading. A motion to have the proposed legislation go into effect at an earlier date was defeated with only 8 votes in favor. The legislation was issued in the National Legal Gazette (Liechtensteinisches Landesgesetzblatt) on 25 April 2023 and went into effect on 1 June 2023.

 * a. Part of the VU-FBP Coalition under Prime Minister Daniel Risch.
 * b. In separate votes, Patriotic Union MP Mario Wohlwend voted in favor of the "Amendment of the Partnership Law", but against the "Amendment of the General Civil Code".
 * c. Served as a substitute deputy for Dietmar Lampert around the time of the debate & vote.
 * d. Served as substitute deputies for Sebastian Gassner & Sascha Quaderer around the time of the debate & vote.

Discrimination protections
On 22 February 2005, following a department reorganisation, the Department of Equal Opportunities (Stabsstelle für Chancengleichheit) was assigned to include discrimination on sexual orientation in its area of responsibility.

The Act on Media (Mediengesetz), enacted in October 2005, declares that media content will be considered illegal if it incites or supports discrimination based on racial or ethnic origin, gender, religion, age, disability or sexual orientation.

Since 1 April 2016, harassment and incitement to hatred on the basis of sexual orientation has been banned in Liechtenstein, punishable by up to two years' imprisonment. Section 283(1) of the Penal Code states:
 * (German): Mit Freiheitsstrafe bis zu zwei Jahren ist zu bestrafen, wer öffentlich gegen eine Person oder eine Gruppe von Personen wegen ihrer Rasse, Sprache, Nationalität, Ethnie, Religion oder Weltanschauung, ihres Geschlechts, ihrer Behinderung, ihres Alters oder ihrer sexuellen Ausrichtung zu Hass oder Diskriminierung aufreizt.
 * (English): Any person shall be punished with imprisonment of up to two years who publicly incites hatred or discrimination against another person or any group of persons on the grounds of their race, language, nationality, ethnic origin, religion or ideology, their gender, disability, age or sexual orientation.

Section 283(6) of the Penal Code prohibits discrimination in public facilities on the basis of, among other categories, sexual orientation.

Blood donation
Liechtenstein follows the same blood donation rules as Austria, where blood donation rules have been non-discriminatory toward LGBT people since summer 2022.

Living conditions
A gay and lesbian organization, Flay, was founded in 1998, and organizes social activities for LGBT people in the triangular area between Liechtenstein, Vorarlberg (Austria) and the Swiss Rhine Valley.

Privacy and individual rights are regarded as fundamental assets of Liechtensteiner society. Open and public discrimination against LGBT people is extremely rare and almost completely unheard of. Despite Liechtenstein's reputation as a conservative Catholic nation, same-sex couples and LGBT people more generally face little social differences compared to heterosexuals and are accepted and tolerated. The country is often compared to "a huge family where everyone knows each other and minds their own business with little interference from others". Due partly to the small population, there are no specific gay bars or venues.

A 2017 online poll conducted by the Liechtensteiner Vaterland found majority support for the legalisation of same-sex marriage, at 69%.

Summary table

 * a. (Indirectly categorized as 'reproductive medicine' & 'medically assisted medicine'): Read Sections 2 & 4.2 (pages 12 & 15 through 16 (top paragraph) respectively) of the provided reference link for details.

title: LGBT rights in Liechtenstein


text:
Wikipedia:School and university projects/Ocean Animals

= Ocean Life =

The Anglerfish
There are many types of angler fish. They are split into two groups: the surface angler, and the deep sea angler. The deep sea angler has many color patterns that make it camouflaged on the bottom of the ocean floor. A deep sea angler can be 4-6 feet long and can get up to 60-90 pounds. The deep sea angler eats small to medium size fish. It can eat fish almost half its size because of its huge mouth and razor sharp teeth. It catches its prey by luring it into its mouth with a light that attracts the fish. No one knows how the light works. The deep sea angler lives in the Atlantic ocean. It also lives in the Mediterranean sea which is by the southern part of Europe and northern Africa. The deep sea angler lives over 3,000 feet down on the ocean floor. source Item 9500200547 Grolier Encyclopedia of fish

Brain Coral
The brain coral, an underwater, wave resistant mound, is a fascinating creature of the ocean. It is made of coral, coral sands, and limestone. True to its name, the brain coral actually resembles the human brain. It is a greenish - brown color from algae. It can grow up to 26 feet in width. The species of the brain coral is the Cnidarian. It lives in the Caribbean Sea with fish, prawns, (edible shrimp), barnacles, Christmas Tree worms and other small animals that burrow into the coral reefs. They can live under 100 to 130 feet under water. They are born in one spot band stays there for the rest of its life. You may have seen brain coral in a souvinier or gift shop. Coral is a very popular souvenir, and such popularity is endangering coral reefs around the world. Although brain coral itself is not in danger, the reefs where the live are being destroyed. This is why it is illegal to import coral in many countries, including the United States. The Crown of Thorns sea star eats brain coral. Usually, brain coral eats plankton. They get nutrients from algae. In return, the brain coral gives minerals to the algae. Although their diet is very important, it isn't included in the four enviormental facts that effect growth. The four enviormental facts that effect the brain coral are temperature, salinity, ( the amount of salt in the water), wave action, and temperature. Brain coral lives in temperatures of 73 to 80 degrees farenhiet. High rates of rainfall or runoff (rain or snow that goes in to the water) may kill coral reefs by reducing salinity. Amazing Animals of the World Vol. 5. Published by Grolier Education Corp. Edited by Molly Stratton1995 Academic American Encyclopedia Vol. 3 1989 ISBN 0-7172-2024-9

Clownfish
The clownfish grows to be between 2 and 5 inches. They have brightly-colored bodies. They are often decorated bright wih yellow or blue stripes. Clownfish have deep thin bodies. The clownfish has a fin on its back. It's called a dorsal fin, it helps the clownfish keep balance. Another fin is called the pectoral fin. That fin paddles it through water. The tail helps it propel through water. Propel means to push. Clownfish are salt water fish. They live in sea anemones. Clownfish can swim ad rest around the sea anemone tentacles without getting stung. Clownfish start off the relationship with the anemone carefully. It spends less time around the tentacles. After a period of time the clownfish feels safe around the tentacles. The relationship between the clownfish and the anemone makes it easier for the clownfish to get food .The clownfish swims away from the reef to attract bigger fish. Then it swims back into the anemone. The anemone poisons the fish with its tentacles. The clownfish eats the remains of the fish. Clownfish also eats algae which is a plant without a stem. It also eats crustacean which is crab, lobster, and shrimp. Sometimes clownfish is born as a male and changes it gender to a female. Gender is a male or female. The female clownfish is bigger than the male. Female clownfish are known to bite at any diver that gets to close to the male or babies. Published by Grolier Education Corp. Encyclopedia of Animals #9500200615 EBSCO Publishing http://www.clown.fish-tropical.net/

Humpback Whale
Humpback Whales are incredible animals. Humpback Whales have sleek (smooth and shiny) gray bodies that point down twards their snout (nose). They have a tailfin, a very small dorsal (back) fin, and 2 small flippers (fins). Whales can weigh up to 50-60 tons (1ton equals 2,000 pounds) and its size can be 50-55 feet. Humpback Whales got their names from hunters for mving the way it does when it dives or rolls over. Before it dives it inhales air and water. When it goes under water it exhales the air and water. They blow it threw a blowhole from the top of its head. Their blow is so powerful that it can lift up a vapor jet (a extreamly heavy military jet) more than ten feet into the air. When it gose under water it covers its blowhole and holds its breath for nearly an hour. A Humpback Whale has no preditors (a creature that kills and eats its pray) until it dies. Humpback Whales eat platon and small fish. Whales talk in different ways they click, rumble groan and whiste. For years hunters have hunted whales for their blubber (fat) for oil lamps. Humpbacks are easy to catch because they like to stay close to shore. Humpback Whales are one of the fewest animals who are unafraid of humans. The Humpback Whales live in the Pacific and Atlantic ocean. The ones in the Pacific ocean mate in April and the ones it the Atlantic ocean mate in September. Humpbacks give birth to one calf (baby). The calves can weigh up to 2 tons (1 ton equals 2,000 pounds). Humpback Whales have the life spand of up to 95 years. resourses: Amazing Animals of the World, Published by Grolier Educational Corporation in 1995 Encyclopedia of Animals Item # 9500200115 Encyclopedia of Amazing Animals


text:
Talk:Cholesky decomposition

Lack of definition of in Monte Carlo example
In the Monte Carlo example application of Cholesky decomposition, \rho is never explained — Preceding unsigned comment added by Matrixalgebrauser (talk • contribs) 04:45, 28 February 2014 (UTC)

Rank one Update and Downdate
These two terms are not defined anywhere in Wikipedia, and searching on the web turns up few references. This terminology is not common, and should be explained.Eigenguy (talk) 01:04, 25 July 2012 (UTC)

Hermitian property
Shouldn't A be symmetric or Hermitian ?

 * A is positive definite, and all positive-definite matrices are Hermitian (see positive-definite matrix). I hope this concise explanation suffices. -- Jitse Niesen 14:13, 26 Apr 2005 (UTC)

 * Is the "all PD matrices are Hermitian" fact available in Wikipedia? I don't know who wrote the original question, but to be fair, the Wikipedia definition: positive-definite matrix gives only the properties that a Hermitian matrix (M) must have to be PD, but doesn't explicitly say than a non-symmetric or non-hermitian matrix can't be PD. Ideally, this would be stated or derived among the 'properties' listed on the positive-definite matrix page, rather than here on a talk page.

Wragge 15:17, 2005 Apr 26 (UTC)
 * (In case there is any confusion, not all Hermitians are PD, so this page, Cholesky decomposition, is fine as it is.)

 * As I feared, my explanation was not well formulated. What I meant to say is that a positive-definite matrix is by definition a Hermitian matrix A such that v*Av > 0 for all nonzero vectors v. So, it is built into the definition that Hermitian matrices are positive definite. You (Wragge) are right that this is not stated explicitly in the article positive-definite matrix.

 * The question which Wragge probably wants to see answered is: if you know that v*Av > 0 for all nonzero vectors v, does it follow that A is Hermitian? If we are restricting ourselves to the reals, the answer is no: there are real matrices A which are not symmetric, but which still have vTAv > 0 for all nonzero real vectors v. I need to check what happens for the complex case; one complication is that v*Av is not necessarily real if A is not Hermitian.

 * I'll check some books when I have time to make sure I've got the details right and rewrite positive-definite matrix if necessary. -- Jitse Niesen 16:57, 26 Apr 2005 (UTC)

PD MUST BE HERMITIAN IN DISPUTE
Thanks for the simple explanation Jitse, I wasn't sure whether all matrices, A, where v*A.v > 0 were Hermitian or not.

Isn't that the general definition of PD though? Is it specified that A must also be Hermitian to qualify as PD? Based on my hazy education, and what I see on Wolfram Research, and Computation Methods in Linear Algebra I am forced to dispute this definition.

Everything I've seen specifies simply the first condition (the multiplication property) and not the Hermitian property (Planet Math fudges the issue by saying that "If A is a square Hermitian then ... is it a positive definite matrix", without saying that this is the non-Hermitians with the same property are not. I have seen no definitions explicitly specifying this condition.) For instance, the definition Google uses, from University of Waterloo simply says :
 * Positive definite matrix (A). x'Ax > 0 for all nonzero x.

Importantly, Computation Methods in Linear Algebra Proposition 6.2.2 clearly implies:
 * 1) Being Hermitian is not a condition for a matrix to be PD (because it states that both conditions must be fulfilled for Cholesky factorization to succeed they must be logically independent).
 * 2) Therefore, the Cholesky decomposition page must make this condition (symmetry/Hermitian) explicit, as the original questioner requested

I conclude that the original questioner raised a useful & correct gap in the definition, but if I have made a mistake, It would be interesting to see where. Can you tell me why you (Jitse Niesen) think that Matrices, A, where all non-zero v vectors give: v*A.v > 0 must also be Hermitian to qualify as a positive-definite matrix?

I only work with symmetric matrices, and most programs and references refer to "Positive Definite Symmetric" as a subset of "Positive Definite", implying that there is no such thing as "Asymmetric Positive Definite Matrix". If such a thing does exist, then some people (me anyway) would be interested in a topic or heading with that name, and an example. It would be one of the few on the Internet.

Also, I am not a pure mathematician, so please forgive any basic errors in understanding that I may have made. I don't know if this is relevant, but the structure of "Definite bilinear form" has the same "if Hermitian then PD" form, without saying "iff Hermitian then PD". Even if this is right, I think it should be cleared up.

- Wragge 22:19, 2005 Apr 28 (UTC)

 * I pulled some books from the shelf and they disagree on this issue. Most use a formulation like "A Hermitian matrix A is positive definite if v*Av > 0," which is ambiguous. Some imply further on that they consider being Hermitian to be a condition for a matrix to be positive definite and some imply that Hermitian and positive definite are independent properties. So, I think it is safest to stress in this article that we need A to be both Hermitian and positive definite. I wrote a small discussion over the relation between positive definite and Hermitian at Positive-definite matrix. -- Jitse Niesen 21:33, 29 Apr 2005 (UTC)

Thanks, Jitse. The Positive-definite matrix is a good summary, with a nice example. I think the reason for the ambiguity is that non-Hermitian matrices have so few applications that the literature concentrates on SPD matrices. Anyway, I don't know enough to take this any further, perhaps it's something to watch out for, if you are looking through textbooks - Wragge 21:47, 2005 Apr 29 (UTC)

The semidefinite case
Question:

The page says that only a positive-definite matrix may be factorized as seen. Are positive-SEMIdefinite matrices excluded from this factorization?
 * I added a paragraph to address this question. -- Jitse Niesen (talk) 04:37, 10 May 2006 (UTC)

 * In that case, the Cholesky–Banachiewicz algorithm has a flaw for semidefinite matrices. To compute $$L_{i,j}$$ below the diagonal, it divides by $$L_{j,j}$$, which could be zero in the semidefinite case. I have seen code that checks for this and just sets the cell to zero, but I am not terribly confident that this is the right way to handle it. Anyone know? --Dave.rudolf (talk) 18:32, 24 January 2011 (UTC)

 * Quick search found the article "Analysis of the Cholesky Decomposition of a Semi-deﬁnite Matrix" analyzing the numerical stability of Cholesky decomposition for symmetric positive-definite matrices with pivoting. I only read the beginning, but it refers to LINPACK routine SCHDC from 1979 which does it, so algorithms for the semidefinite case are not new (the numerical stability analysis article is from 2008, though!). It would be nice if the Wikipedia article treated the semidefinite case as well. -- Coffee2theorems (talk) 10:29, 28 July 2012 (UTC)

 * I believe that the proof given for the positive semi-definite case has a flaw, and I think several simplifications can be made in other areas. First, regarding the part which says "by property of the operator norm", I do not see which property is being used, and in fact I believe that the inequality is the opposite way. Second, to show $$A = LL^*$$, we do not need to go through inner products.Suncup224 (talk) 10:36, 30 December 2013 (UTC)

 * The introduction of the article says positive-definite, the statement paragraph state positive-semidefinite. We should be consistent with the definition Raffamaiden (talk) 16:02, 1 May 2013 (UTC)

 * I checked three references and all of them define initially the Cholesky decomposition only for positive-definite matrices and they're not clear on whether the name also applied to positive-semidefinite. I changed the statement paragraph to be closer to the references. -- Jitse Niesen (talk) 15:20, 2 May 2013 (UTC)

The real matrix vs. complex matrix decomposition
I belive the formulas given for the decomposition relate only to real (real SPD) case. I think they should be generalised to the complex Hermitian positive-definite case. Than they will look like that:

$$l_{ii} = \sqrt{a_{ii} - \sum_{k = 1}^{i - 1}{|l_{ik}|^2}}$$

$$l_{ij} = \frac{1}{l_{jj}} \left( a_{ij} - \sum_{k = 1}^{i - 1}{l_{ik}\bar{l}_{jk}} \right)$$

One more question came to my mind...Why do we consider only positive-definite matrices in complex case??? There exists square root for any complex number (not unique however). So we should be able to use above formulas for any Hermitian matrix (not necessarily PD). Of course the diagonal elements of L would not be positive reals anymore.

What is more, we should be able to use the original formulas for symmetric real case in symmetric complex case. So why do we care about positive-definitness???

--A-lbi 09:49, 22 August 2007 (UTC)

Possible mistake?

 * $$ l_{i,i} = \sqrt{ a_{i,i} - \sum_{k=1}^{i-1} l_{i,k}^2 }. $$

Are we sure $$\sum_{k=1}^{i-1}$$ is right? For the first value of the matrix we have i=1, so:
 * $$ l_{1,1} = \sqrt{ a_{1,1} - \sum_{k=1}^{0} l_{1,k}^2 }. $$

So k goes from 1 to 0? Also, the next value is (i = 1, j = 2):

 * $$ l_{i,j} = \frac{1}{l_{j,j}} \left( a_{i,j} - \sum_{k=1}^{j-1} l_{i,k} l_{j,k} \right), \qquad\mbox{for } i>j. $$

 * $$ l_{1,2} = \frac{1}{l_{2,2}} \left( a_{1,2} - \sum_{k=1}^{0} l_{1,k} l_{2,k} \right)$$

Again the sum seems strange. —Preceding unsigned comment added by 84.223.150.164 (talk) 21:54, 27 March 2008 (UTC)

 * By convention,
 * $$ \sum_{k=1}^{0} l_{1,k}^2 = 0, $$
 * see empty sum. So, for the (1,1) entry, we get
 * $$ l_{1,1} = \sqrt{ a_{1,1} - \sum_{k=1}^{0} l_{1,k}^2 } = \sqrt{a_{1,1}}. $$
 * Indeed, if we look at a 1x1 matrix [a], then its Cholesky decomposition is [a] = [l]* [l], so l is the square root of a. So at first sight everything seems fine. -- Jitse Niesen (talk) 22:23, 27 March 2008 (UTC)

Pivot?
As someone who doesn't know much about mathematics, could there be a definition (or a link to a definition) on what is meant by pivot in the sentence "Any square matrix A with non-zero pivots can be written as the product of..."? Please forgive my ignorance but hey - that's why I'm reading the article in the first place ;-) —Preceding unsigned comment added by 158.234.250.71 (talk • contribs) 16:30, 1 July 2008

Bump for this one: it would be useful to have an description of the pivoting procedure. — Preceding unsigned comment added by 128.125.86.205 (talk) 20:35, 5 August 2013 (UTC)

BigO of Cholesky vs LU?
I added a numerical recipes cite in the first paragraph and changed the sentence to read "roughly half" instead of "half [as many operations]". It is still possible that Cholesky decomposition requires literally half as many operations but we should cite a source before saying so. I found several other sources that imply it is but that never say specifically. Jason Quinn (talk) 13:07, 29 January 2009 (UTC)

 * Trefethen and Bau (Numeical Linear Algebra, 1997) say it is 2/3 m3 flops for LU (pp 152) and 1/3 m3 flops for Cholelsy. PDBailey (talk) 00:24, 30 January 2009 (UTC)

 * They ignore lower order terms, though. I think it would be quite a coincidence if the number of operations were exactly halved. -- Jitse Niesen (talk) 13:36, 30 January 2009 (UTC)

 * You should add the Trefeten reference to the article. Probably a large segment the of the readership of this article will be interested in the big-O order. Jason Quinn (talk) 17:20, 30 January 2009 (UTC)

 * How does it make any sense to talk about FLOPS? How many steps an algorithm takes has nothing to do with either floating point operations nor how many are performed per second. Giving the order of the number of steps in Landau notation doesn't really help as a comparison to LU decomposition either.Steve Checkoway (talk) 23:11, 24 January 2011 (UTC)

The Cholesky-Banachiewicz and Cholesky-Crout algorithms ??
The hyphenated terminology -Banachiewicz and -Crout does not exist in numerical analysis. The use of these phrases is an attempt by someone to create a historical reference that is not appropriate. I sympathize with whoever was the author, because Banachiewicz and Crout did have something to do with solving linear systems and deserve more credit. However. if that history is wanted, a proper history section should be added rather than the made-up names. :-) Jfgrcar (talk) 02:21, 26 September 2009 (UTC)

Hermitian case when not pos-definite
With some web searching, I found many people asking why we need the positive definite restriction in the complex (Hermitian) case, but didn't find anyone attempting an answer. In the real case, the algorithm gives us a way to detecting non-positive-definiteness, but how do you do that in the complex case?

I notice that in the complex case, you end up with:

$$l_{ii} l_{ii}^* = a_{ii} - \sum_{k = 1}^{i - 1}{|l_{ik}|^2}$$

If the right-hand side is not positive real, I don't think you can find $$l_{ii}$$. Notice that it isn't a straight square root, because the diagonal term times its conjugate must be equal to the right-hand side, as opposed to the term times itself.

Do either or both of these conjectures hold (when a is Hermitian)?:
 * if a is not positive definite, then $$a_{ii} - \sum_{k = 1}^{i - 1}{|l_{ik}|^2} \le 0$$ for some i.
 * If $$a_{ii} - \sum_{k = 1}^{i - 1}{|l_{ik}|^2} \le 0$$ for some i, then a is not positive definite. —Preceding unsigned comment added by 67.160.223.41 (talk) 23:02, 13 December 2009 (UTC)

Upper triangular
I know that many built in functions into programs to compute this decomposition use an upper triangular formulation. Although lower triangular is definitely more classic, isn't the upper triangular version ie. XtX = UUt also a cholesky decomposition MATThematical (talk) 23:18, 14 March 2010 (UTC)

Intuition?
I understand intuition of eigendecomposition of a Hermetian matrix (for a covariance, it's the variances in principal directions; for a coordinate transformation it is similar). What is the intuitive, physical meaning of Cholesky decomposition? There must be some interpretation...? —Ben FrantzDale (talk) 05:05, 19 April 2010 (UTC)

I hope (as usual) that someone can correct me if I've got the wrong idea, but I think that roughly speaking Cholesky decomposition is from a conceptual-geometric viewpoint an obfuscated version of Gram-Schmidt orthonormalization. With vanilla Gram-Schmidt you orthonormalize a non-standard basis with respect to the standard inner product, whereas with Cholesky decomposition you orthonormalize the standard basis with respect to a non-standard inner product. The matrix being decomposed is that non-standard inner product, and the decomposition matrix is the operator transforming between the orthonormalized basis and the original standard basis.

The more general version of Gram-Schmidt orthonormalization that allows both a non-standard basis and a non-standard inner product specializes either to vanilla Gram-Schmidt (by taking the inner product to be standard) or to Cholesky decomposition (by taking the basis to be standard).

(As requested I'm only trying to address the intuitive picture here, rather than the gritty computational details which might motivate the choice of one algorithm over another in practical situations.)

There's a Math Stack Exchange question on "Cholesky Decomposition and Orthogonalization" with answers from Victor Liu that I hope roughly agree with my description here, although I didn't completely decipher their notation. The wikipedia article on Gram-Schmidt also mentions Cholesky decomposition but again I didn't decipher their full explanation. 68.196.182.19 (talk) 16:35, 29 August 2019 (UTC)

for MC simulation
wouldn't you need to the square root matrix of the inverse of the Hessian, not the square root of the Hessian? 151.200.188.223 (talk) 06:42, 26 February 2011 (UTC)

The cholesky algorithm
In the explanation of the cholesky algorithm, I think the part that relates A(i) to A(i+1) is impossible to understand without knowing how B(i+1) is related to B(i). It feels like something is missing — Preceding unsigned comment added by 83.251.122.201 (talk) 21:11, 15 August 2012 (UTC)

I agree with this last comment, unless you already know how the algorithm works is hard to understand the role of B. On this text "At step i, the matrix A(i) has the following form:" one should stress the sizes of B and b, and that those ones represent a partition of the matrix; also it could be said that when i=1 the top left corner Identity(i-0) and right and bellow zeros do not exist. 83.223.227.96 (talk) 12:34, 9 August 2019 (UTC)

negative complex number
it is said that "L is a lower triangular matrix with nonnegative diagonal entries". L in general is a mtrix with complex numbers. What does it mean that the ocmplex numbers that are on the diagonal are non-negative? — Preceding unsigned comment added by Raffamaiden (talk • contribs) 16:07, 1 May 2013 (UTC)
 * The diagonal entries of L are real. Here is an argument. A is hermitian positive definite, so it has real eigenvalues and is unitarily diagonalizable, and thus has a Hermitian positive definite matrix square root; if A = U D U^H, then S = A^{1/2} = U D^{1/2} U^H, where D^{1/2} has (real) positive entries. S in turn has a QR decomposition S = QR. R is upper triangular with real diagonal entries (the real eigenvalues of S). We have A = S^2 = S^TS = R^H Q^H Q R = LL^H, where L = R^H and thus has real diagonal entries. The cholesky decomposition is unique, so this construction serves to show that the diagonal entries of L are real. Khromegnome (talk) 21:07, 1 May 2013 (UTC)

Cholesky_decomposition
It states
 * $$\| \mathbf{L}_k \|^2 \le \| \mathbf{L}_k \mathbf{L}_k ^* \|.$$

The operator norm is submultiplicative, why should this be the case? --Erzbischof (talk) 11:14, 9 July 2013 (UTC)

 * The case of $$\mathbf{L}_k \mathbf{L}_k ^*$$ is special. For example, in the induced L2 norm (i.e. the operator norm induced by the L2 norm on the vector space), then $$| A |^2 = |  AA^* |$$: $$| A |^2$$ is the square of the maximum singular value of A and this is the same as the maximum singular value of $$AA^*$$.   I'm not sure off the top of my head about other induced norms, but it seems plausible (which doesn't obviate the need for a reference).  Indeed, the whole section lacks references. — Steven G. Johnson (talk) 14:23, 9 July 2013 (UTC)
 * Ah, thank you, so for the spectral norm it holds and then norm equivalence gives a bound anyway. On the other hand, $$| A |^2 = | AA^* |$$ look like a Hilbert space property. --Erzbischof (talk) 21:37, 9 July 2013 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified one external link on Cholesky decomposition. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20110716060800/http://www.eti.pg.gda.pl/katedry/kams/wwwkams/pdf/Cholesky_fmprg.pdf to http://www.eti.pg.gda.pl/katedry/kams/wwwkams/pdf/Cholesky_fmprg.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 16:09, 5 August 2017 (UTC)

title: Talk:Cholesky decomposition


text:
Talk:Single sign-on

Single sign on vs. single sign off
The current version of the article says that "Single sign-off is the reverse property whereby a single action of signing out terminates access to multiple software systems". I think that describing single sign off as the reverse of SSO is not accurate. The reverse would be something like prompting for a username/pwd each time a user accesses a new system in the environment. Opinions?? --Eyad — Preceding unsigned comment added by 217.165.19.30 (talk) 06:37, 28 December 2011 (UTC)

✅ - Reworked the sentence. --M4gnum0n (talk) 09:28, 12 June 2012 (UTC)

Possible conventional authentication support
"Can support conventional authentication such as Windows credentials (i.e., username/password)" The wording of this statement needs improvement, that statement doesn't demonstrate any kind of any additional benefit from SSO that isn't already covered more generally in that list. I could go further to say, if it's not a given, how is it even relevant? Perhaps it should go in a hypothetical use case list.--58.96.105.16 (talk) 14:23, 14 July 2010 (UTC)

✅ - Removed. --M4gnum0n (talk) 09:31, 12 June 2012 (UTC)

ESSO Security Benefits?
In the ESSO section, it seems incorrect to say "significant security upside with client side ESSO solutions" and much like a brochure. In practice, SSO benefits the usability of systems, but does not add to any security. In many cases, this can be detrimental. —Preceding unsigned comment added by 74.140.173.132 (talk) 01:12, 20 October 2009 (UTC)

Use of the em dash
Could someone provide justification for use of the em dash in this term? More common usage seems to be without it ("Single Sign On"). The SNIA Dictionary is going to go without it in the absence of a strong argument for it. Alan Alanyoder (talk) 19:21, 30 May 2008 (UTC)

Yea, I agree with the use of the em dash, that, it should go. I think this confusion is similar to the debate with email and e-mail. It's worth noting that people write "single signon" "single sign-on" and "single sign on" -- I need for the sake of people being able to find this article, we need to think about redirecting anyone typing the above three to this article. Let's make it "single sign on" but make sure we code in "redirections" for those typing any other ways. ken knguyeniii —Preceding comment was added at 05:43, 26 June 2008 (UTC)

Merging with Enterprise Single Sign-on
With respect to merger proposal from Aug. 2007: No discussion seems to have taken place. My vote: MERGE. Vigilius (talk) 21:25, 8 April 2008 (UTC)

I agree: MERGE. ESSO is an element of SSO, although really a different technology. :) —Preceding unsigned comment added by Dpuryear (talk • contribs) 18:36, 24 April 2008 (UTC)
 * Looks like someone already had it merged. I redirected ESSO to this article and removed the tags. Jauerbackdude?/dude. 13:12, 1 July 2008 (UTC)

Sincerely this a support programme for any person Sting omugezi wecilifeli comquer (talk) 12:19, 14 May 2022 (UTC)

SSO internally
Can someone tell me how SSO works internally and how it talks to the IIS server etc...
 * Go look at SPNEGO -- DLeonard 02:53, July 21, 2005 (UTC)

This page just changed from yesterday. There is now an entry regarding CoSign, which is apparently some sort of open-source identity management product. I don't think CoSign should be listed as a type of Identity Management. It appears to me to be a specific implementation of Web Single Sign-On, not a specific category unto itself.Josh (josh.nospam@jrandrews.net)

Reversion as of June 16, 2006
(diff: ) I removed a series of edits which appeared to be advertising; the subject of the edits did not return any relevant Google hits and did not appear to be a highly notable service. If you are the user to made these changes, I apologize for the intrusion and encourage you to see WP:WEB, WP:NOT, WP:AUTO, and WP:SPAM. Especially if I have made these reversion in error, you have my most sincere apologies. If you wish to replace these edits, please offer your reasoning here. Luna Santin 08:46, 16 June 2006 (UTC)

OpenID
Was OpenID overlooked or is there a reason for it not appearing on this page? Pyroman 15:26, 9 August 2007 (UTC)

 * OpenID is an authentication framework while this page speaks of SSO as an access control mechanism in the first paragraph. We can comment somewhere in the Criticism section that SSO is a misnomer, though. Sam lowry2002 (talk) 09:44, 21 April 2010 (UTC)

Zennovation Removed?
Hi.

I added a sign-on provider to the list but it was removed but there was no reason as to why it was. Can anyone tell me why it was removed? Was it the fact that the provider is still in beta while revamping to become a public service or the way I wrote the information about it? —Preceding unsigned comment added by 149.254.200.218 (talk) 00:28, 1 November 2007 (UTC)

 * You're supposed to cite reliable sources when introducing information to Wikipedia; you should *NOT* include external links other than citations.
 * In any case, it doesn't matter, I have removed the list altogether because this article looked like yellow pages rather than an encyclopedia entry. -- intgr [talk] 01:27, 2 November 2007 (UTC)

Ok no problem. I was just wondering, I'm not really an expert of Wiki editing, usually just use it for reference, and I was not going to put and external link in untill I saw one in another, but no problem. Thanks for the info. —Preceding unsigned comment added by 88.109.94.238 (talk) 16:32, 2 November 2007 (UTC)

Enterprise service-oriented architecture
I removed the section on Enterprise Service-Oriented Architecture. That's just SAP's name for SOA. Many of the statements were forward looking: "will have an impact on", "likely that future SSO solutions", etc. Here is the text I removed:

 * Single Sign-On for Enterprise Service-Oriented Architecture
 * Enterprise Service-Oriented Architecture, also known as E-SOA (also see Service-Oriented Architecture), will have an impact on authentication technologies and architectures. It is likely that future SSO solutions will evolve according to new customer needs in real-life E-SOA environments. Furthermore, there is a growing concern over the applicability of current SSO solutions for E-SOA platforms provided by SAP or Oracle Corporation. There are new developments in SSO technology designed to offer "E-SOA compatibility."
 * Client Certification-based SSO in E-SOA
 * Client certificates is an authentication method that supports a secure single sign-on to some ERP E-SOA based platforms (e.g., SAP)
 * Kerberos-based SSO in E-SOA
 * Some E-SOA platforms will not be compatible with Kerberos-based SSO. SAP E-SOA is one example.
 * Supported SSO Mechanisms for SAP E-SOA
 * 1) Username / password
 * 2) Client Certificates
 * 3) SAP Logon Tickets
 * 4) SAML (combining SAML and Kerberos not planned)

Maybe this wants to go in the SAP article? --Ishi Gustaedr (talk) 21:01, 10 July 2008 (UTC)

Agreed. this should go in the sap article. this could also go into the service-oriented architecture article...i don't think there is an e-soa article yet. it would be nice to have someone build it.

OpenID can be an SSO system
The article contains the claim "Shared authentication schemes like OpenID, which require additional sign-on for each web site, are also not single sign on".

First of all, OpenID would not generally be considered a shared authentication scheme. When you use an OpenID to log in to a relying party, the relying party doesn't directly authenticate the user: instead it asks the OpenID provider whether the user is authenticated. The relying party never has enough information to independently identify the user, which is the usual case for shared authentication.

While not required by the spec, most OpenID providers only require the user to authenticate once during a session (e.g. using session cookies or relying on SSL client certificates that the user unlocks once). So in most cases, the user only signs on a single time.

Lastly, it is quite easy to build a traditional closed SSO system with a central authentication server using OpenID 2.0's directed identity mode. This could either be a company provider for intranet apps, or as a way to rely on Google's or Yahoo's account systems for an internet app. --James (talk) 15:08, 12 May 2009 (UTC)

 * Makes sense; are there any sources that discuss using OpenID as a SSO system? If so, I can't see any problems with changing this. -- intgr [talk] 22:08, 12 May 2009 (UTC)
 * I've built such systems, but haven't published anything on it. There is Google's documentation on implementing federated login here which might count: it describes using a fixed endpoint URL and directed identity to start the authentication process without having the user provide an identity URL, which is pretty much how the systems I've built work. --James (talk) 23:55, 12 May 2009 (UTC)

"See also" subsections
The "see also" section seems to be rather lengthy, perhaps we could organize it under a few subheadings? I will try to get around to it sometime soon, but I invite the rest of you to give it a go. ...but what do you think? ~B F izz (talk) 22:36, 20 August 2009 (UTC)

 * i agree that it is rather long. The suggested reorganisation would probably be an improvement, but I think better still would be to cut most of it out: some of the topics are fairly indirectly related, and it seems to me "see also" sections should give just the most significant links. JamesBWatson (talk) 09:08, 14 December 2009 (UTC)
 * I reorganized the content under the headings "Underlying concepts", "Related technologies", and "Implemetations of single sign-on". Unfortunately, I'm really not knowledgeable enough to determine what to delete, but perhaps we should break the "Implementations of single sign-on" section into a list of its own: List of implementations of single sign-on. Then we could simply "see also" a link to that list. ...but what do you think? ~B F izz (talk) 18:45, 15 December 2009 (UTC)
 * Since it seemed like the thing to do, I did it. The see also section now has only 4 links. =) Please review the changes and comment/act thereupon. ...but what do you think? ~B F izz (talk) 18:58, 15 December 2009 (UTC)
 * Much better. Thanks. JamesBWatson (talk) 15:06, 7 January 2010 (UTC)

SAML
I'm a newcomer to this topic, but I was surprised to see no mention of SAML. Is that intentional? The SAML page currently says "The single most important problem that SAML is trying to solve is the Web Browser Single Sign-On (SSO) problem" which makes it seem relevant. Chris Dolan (talk) 19:21, 22 August 2011 (UTC)

✅ - Added a link in the "See also" section. --M4gnum0n (talk) 09:47, 12 June 2012 (UTC)

Resources
I am posting a white paper about this topic under resources and it keeps getting deleted. Does anybody know why? — Preceding unsigned comment added by DParisotti (talk • contribs) 15:46, 12 September 2011 (UTC)

 * If you click View History on the article, then you can see the edit summary given by the editor who reverted your change. The reason given was that the link you added requires some form of sign-up (or at least, surrender of personal information) for use. This is not permitted for external links; see WP:ELREG. From a brief glance, the "white paper" you tried to link to, also seemed aimed at selling some sort of support service or similar product. That's not what Wikipedia is for. --Demiurge1000 (talk) 16:52, 12 September 2011 (UTC)

Definition
SSO is not a property, but a capability offered by access control systems — Preceding unsigned comment added by Mullachv (talk • contribs) 05:04, 1 December 2012 (UTC)

I am not sure I agree with "...single sign-on has to internally translate to and store different credentials compared to what is used for initial authentication..." near the top. I agree that one method of implementing an SSO solution would be to store a bunch of credentials and do look-ups against some initial credentials. Another approach is to have different systems collaborate to use a single set of credentials provided by a central identity provider, and to have secure message exchange between the identity provider and parties that rely on that provider.

I understand that implementing such an identity provider involves maintaining sets of certidicates or name/password pairs that underlying systems use to know each ohter, but this is not the same as maintaining a set of credentials for each user that authenticates with the SSO. A name and password that identifies the accounting system is not quite the same concept as a name and password for each user of the accounting system.

I don't know that I have a good replacement sentance for the one I don't like. I might just erase the sentance, but that would maybe beg questions.

Contrast ESSO used by Microsoft BizTalk with Access Control Services used in Microsoft Azure

--Skip (talk) 17:19, 5 February 2013 (UTC)

Reopening discussion about SSO versus OpenID, to include OAuth, OpenID Connect and Facebook Connect.
I just updated the opening section of the single sign-on article to try to distinguish between true SSO (based on the work of the formal user groups and how Google federates all their apps), versus OPenID, OAuth, Facebook Connect, etc, where I thought you have to sign in each time. I included a source saying that OpenID was not technically SSO, but instead is pluggable authentication with a shared database []. I also looked at the different standards bodies to get info direct from the source. Opengroup.org has a page showing how SSO is supposed to work, where the login info is passed to the secondary sources without the user having to do anything but click.[]  The National Information Standards Organization (NISO) has an SSO initiative called ESPRESSO where they are trying to draft true single sign-on, and in the call for the draft document they specifically mention Athens and Shibboleth as being true SSO, but only if the participating sites have agreed on which one to use.[]  I went to the OpenID COnnect site and found their spec, and it does say that the OpenId process can be automatic, at least that's how I'm reading section 3.1.2.1. Authentication Request on []. My personal experience is that I'm prompted every time - I've never gone to a web site where I was automatically logged in and it said "Welcome Tim" or something like that on the top.

I looked in the other comments on this talk page and saw that there were two old previous discussions about this - one saying SSO and OpenID are different user:Sam lowry2002, and one saying they were the same, but without providing any sources user:JamesHenstridge. Here's a blog listed as an external link which heavily mixes and matches the terms SSO and OpenID []. I"m not sure what's right. Anyone have any additional insight about OpenID and whether it is expected to function as true SSO?  If not, the entire security section, which only discusses OAuth, needs to be updated.Timtempleton (talk) 15:44, 23 May 2014 (UTC)

 * I said that OpenID can be used to build a Single Sign-On system, and I stand by that. I agree that many sites implementing OpenID are not implementing SSO, that doesn't mean that OpenID can't be used to implement it.

 * Rather than requiring the user to click a "log in" button, there is nothing stopping Relying Party web sites from starting the authentication process without prompting by the user. This could either be done when the user first visits the site or when they do something that requires authentication (e.g. as part of the checkout process on a web store, editing a wiki page, etc).  If you want to do this without user interaction, you'd need to use a fixed identity URL to start the authentication procedure.  With OpenID 2.0's identity select mode, this isn't such a problem: you can use an Identity Provider's identity URL instead.  In this way, the IdP can authenticate as any identity URL it manages in the response.

 * On the Identity Provider side, it knows which RP it is talking to and knows who the user is through browser credentials (cookies, client certificates, basic or digest auth, etc). While the IdP could ask the user if they want to provide their identity to the RP, if could also complete the authentication process for recognised RPs without user interaction.  If you put these two together, an RP could transparently authenticate a user provided they have previously authenticated to the IdP. --James (talk) 02:40, 10 June 2014 (UTC)

Add Atlassian Crowd reference
https://www.atlassian.com/software/crowd/overview/ — Preceding unsigned comment added by 190.216.150.147 (talk) 13:37, 14 March 2016 (UTC)

title: Talk:Single sign-on


text:
Beatservice Records

Beatservice Records (established 10 October 1994 in Tromsø, Norway) is a Norwegian record label releasing electronic music. It was initiated by Vidar Hanssen who was DJing for a local student radio with the program The Beatservice Radio Show at the time. Beatservice Records have released music ranging from minimalistic ambient via house and experimental techno to drum and bass. The label was an important factor in the mid-to-late 1990s popularity of the Tromsø based electronic music scene, both in Norway and elsewhere.

It has released music by artists such as Biosphere, Elektrofant, Aedena Cycle, Kolar Goi, Flunk, Ralph Myerz, Xploding Plastix, Teebee, Sternklang, Kim Hiorthøy, Howard Maple, Bjørn Torske and Frost.

title: Beatservice Records


text:
Wikipedia talk:School and university projects/Ocean Animals

Notes from your Classmates
General Questions
 * Can we include the Howler Monkey? - Jane

Source Questions
 * Can we cite the A-Wing Slash article?

Editing Suggestions Did you misspell the word cite in the opening paragraph? - Joe No I didnt.. -Heather

Other Suggestions

Speedy Deletion
I returned the speedy deletion template, which was removed by the creator of this article with no reason given. To the creator: if you wish to have the template removed please discuss it here on the talk page. --Canderson7 18:50, May 4, 2005 (UTC)

This page is a school project, however, the students are researching all that they report, and are citing sources as any good scholar should do. I do not see why this would make the page a candidate for deletion. We are trying to add to the body of knowledge. We are editing this as a class, and are planning on continuing to add to the page. As a teacher, I am planning on using this page and adding to it each year with each new class. Please explain why this does not meet the standards and stated mission of the Wikipedia. User: 209.173.17.194 (G. Gambill).

 * This is besides the point for the time being because this page has been labeled as possible copyright infringement, but I will still be welcome to explain myself. I do not feel that there were any grounds for the speedy deletion of the page, however the template was removed without due process and I was simply returning it for that reason while I looked up Wikipedia policy in order to confirm my belief that it was not a candidate for speedy deletion.  I have found this to indeed be the case, but now more appropriate action has been taken.  --Canderson7

Can I explain what is going on here. First, the page is not a speedy deletion candidate - to be that is must essentially be nonsense. What you should do if this happens is to explain why the page should not be deleted here on the talk page. Don't worry, no admin is going to delete the page when it looks like it did and has talk on its talk page.

However the issue with the page is that is doesn't fit in with the rest of Wikipedia. A page on Ocean Animals should really give an overview of all the animals that live in the ocean. Instead of having a section on Brain Coral, the information about Brain Coral should go in the article on Brain coral. I understand that getting students to do this and getting them to interact with the other Wikipedia users is going to be a problem.

I marked the article as possible copyright violation because it cited an encyclopedia article for every section. Usually that means that someone has just copied a whole encyclopedia into Wikipedia. If you can assure me that that is not the case, and everything has been rewritten in the student's own words I'm happy to remove the notice and revert to the working version.

Maybe your students could actually add info to Brain coral etc. That would be much more in keeping with the Wikipedia project. DJ Clayworth 19:17, 4 May 2005 (UTC)

Mr. Clayworth. Thank you for your insight. I can assure you that the information has been restated from a three source research project. The students have, of course, copied facts and figures given such as average length, age etc, but the rest has been paraphrased from the sources listed. It appears as though by listing sources, we have sent up several red flags. It was my assumption that this was a good thing to do so that others could view and check our sources. If this is not the case, please let us know. The whole goal of this page was to try to give an encyclopedia article page that would be kid friendly. This is why my students explain terms such as "dorsal" and "blowhole". We have found that most encyclopedias are so technical that they are unusable for younger learners, hence the idea for this project. It was our hope that by providing this resource, and adding to it over the years, collaborating with others, we could make a reference that would be useable and understandable to kids and adults alike. Is this really such a bad idea? This is an honest question, I would welcome your thoughts since you responded so cordially and seem to be trying to be helpful. As an aside, this project has an alternate learning goal of promoting scholarship, writing and editing (we edit as a group. This page, before it was taken away, for example, was edited by the students last night as a homework assignment). This editing will help to ensure accuracy and reliability of the information. We are fully aware that others will be looking at our information, so we have a responsibility to be accurate. It was also my understanding that this editing process would not trouble anyone as I thought that the page would be an unseen "orphan" until we linked it to the main encyclopedia though another article. Apparently, thi is not the case. In regards to your suggestion, we would prefer to make a single page, and build on it year after year. If, however, this is viewed as unacceptable to whoever is in chare of the wikipedia, we will either abandon our work, or try to follow your suggestion of adding to an existing article. This will not centralize this resource, however, which was a goal of mine. What do you think? I would welcome your feedback. User: 209.173.17.194, G. Gambill

School Project
Mr./Mrs./Ms. G. Gambill, please see School and university projects - instructions for teachers and lecturers--Duk 16:57, 12 May 2005 (UTC)
 * I'll second what Duk just said above. Furthermore, the content of this article is already covered in other articles; Anglerfish, Brain coral, Clownfish, Humpback Whale. I note that brain coral is a stub. Your students could enhance that article significantly. However, creating a new article such as this one that has information that exists in other articles is not appropriate. I encourage you to see the link that Duk posted above. --Durin 05:01, 24 May 2005 (UTC)

And also see Naming conventions. --Dmcdevit 22:58, 24 May 2005 (UTC)

Copy vio
Copyvio has been removed (misunderstanding between source citing and copyright violation)--Duk 16:57, 12 May 2005 (UTC)

Speedy delete
I don't see that this article meets Criteria for speedy deletion, so I have not restored the speedy tag after taking off the copyvio tag. Article needs to go through VFD if anyone is so inclined. --Duk 16:57, 12 May 2005 (UTC)


text:
Wikipedia:Articles for deletion/Era of Good Feelings

 This page is an archive of the discussion about the proposed deletion of the article below. This page is no longer live. Further comments should be made on the article's talk page rather than here so that this page is preserved as an historic record. The result of the debate was redirect to Era of Good Feeling. – Rich Farmbrough 18:27, 1 May 2005 (UTC)

Era of Good Feelings
Delete. There is a longer and better article on the same topic Era of Good Feeling. -- Mwanner 13:33, Apr 26, 2005 (UTC)
 * If there's anything worth saving Merge. Then Redirect. Kevin Rector (talk) 15:14, Apr 26, 2005 (UTC)
 * Redirect. Everything mentioned is explained in greater detail in the Era of Good Feeling article. -- Trivial 19:33, 26 Apr 2005 (UTC)
 * Redirect. Gazpacho 20:54, 26 Apr 2005 (UTC)

 * This page is now preserved as an archive of the debate and, like some other VfD subpages, is no longer 'live'. Subsequent comments on the issue, the deletion, or the decision-making process should be placed on the relevant 'live' pages. Please do not edit this page.


text:
Talk:Contrast ratio

2008
contrast ratio is also a cinematography term that is not (yet) covered well within the article.

"Many display devices favor the use of the full on/full off method of measurement, as it cancels out the effect of the room and results in an ideal ratio. Equal proportions of light reflect from the display to the room and back in both "black" and "white" measurements, as long as the room stays the same. This will inflate the light levels of both measurements proportionally, leaving the black/white luminance ratio unaffected."

This seems to be magic ... a constant delta in enumerator and denominator of the ratio will surely produce a reduced quotient. Also it is probably not the desire of the display device which method of measurement it favours. This statement is just wrong.

panjasan
 * I'll explain what I meant. Suppose you're doing a measurement in a completely non-reflective room and you're looking at a 1000 lumen screen at 100% white. The projector produces, say, 10 lumens for that screen at 100% black input signal. You'll get a 100:1 measured contrast ratio for that setting. Now if the room were to reflect some of the light back, it would do it with equal ratios for both the black and the white signals - for example, 10%. This would produce 1100 lumens for white signal and 11 lumens for the black signal, and still a 100:1 measured contrast ratio. The reflectivity of the room would then be cancelled out. Do you have another wording in mind that would demonstrate this concept in a more understandable fashion? Santtus (talk) 22:38, 19 May 2008 (UTC)

is this the ANSI contrast? Actually, the darkest color is black, and that means zero luminosity (should be not hard to achive)... the contrast then would have an infinite contrast ratio. thus i guess the contrast ratio isn't that good in telling you about the quality of a display - or am i wrong? thanks, --Abdull 13:34, 26 Apr 2005 (UTC)

It's quite difficult to achieve zero luminosity using any display technology. For example, in DLP projectors some light will reflect from between the mirrors, and some will reflect from the very mirrors themselves. Reflection from aluminum is not completely mirror-like (specular reflection), there will be some diffuse reflection as well, meaning that mirrors that are turned away in a Santtus 22:05, 24 July 2005 (UTC)

Actually CRTs achieve a theoretically infinite contrast ratio and practically achieve enough of one to make such quantification pointless. (comment 23:53, 8 January 2006 Zbobet2012)
 * However, in practice CRT's can't achieve infinite contrast ratios. Four problems: The reflectivity of the surface is not zero, the CRT response is not linear to the ends, and drifts (so you may not be able to uze the dark end of the scale), the circuit response is not linear to the ends, and drifts (so you may not be able to uze the dark end of the scale), and the noise of the input video signal is not zero, so in practice all CRT's have adjustable contrast and brightness, and a noticable contrast ratio variation between units, when you line them up on the bench. —Preceding unsigned comment added by 218.214.18.240 (talk) 00:56, 8 June 2009 (UTC)

 * Checked that fact, you're right. I found something lot more interesting tho. I'll re-arrange the article later on.. lots of stuff that needs to be added. I'll work on that. Added some references already.
 * The static contrast ratio of the eye is just about 0,5-2%, so that a display with 200:1 contrast ratio would suffice, if the average light level in the image would stay the same. The overall light level in the image usually changes, so greater ratios are required. The eye adjusts to various light levels to the extent that about 10^7:1 ratios can be achieved, but mass produced display devices are incapable of such contrast ratios. This is explained to better depth in here.
 * A presence of single candle in an average room will render 30000:1 (or infinite, for that matter) and 500:1 displays indistinguishable from each other. In a typical brightly lit office only contrast ratios of 10:1.. 30:1 can be achieved. In this situation, the determining factors are the ambient light level, reflectivity of the display surface and the maximum luminocity the device is capable of. The slight variations in the lowest blackest levels would be totally lost in the presence of ambient light 10 or 100 times more than that of the device. Santtus 11:58, 11 January 2006 (UTC)

Removed the unsourced template
I added sources to perhaps one half of all the statements that could use one. I'll try adding some more references soon. Santtus 12:06, 11 January 2006 (UTC) Oops, sorry I'm late from addding references. Btw one thing.. I guess that someone mixed having ability to resolve brightness levels 1% apart (1:100) and having 100:1 resolution. Santtus 21:15, 5 March 2006 (UTC)

New reference format
I've updated the first couple notes to the new format, which can match up the numbers more accurately. Shawnc 23:19, 20 April 2006 (UTC)

This sentence
"This may not sound too bad though, as the static contrast ratio of a human eye is somewhere between 100:1 - 1000:1 so the details in those highlights might not be resolvable anyway." This can probably use a citation and be re-worded a bit, in particular "sound too bad" and "might not be resolvable". Shawnc 00:06, 21 April 2006 (UTC)
 * That 100:1 - 1000:1 thing was from an article, although I summed up the controversy surrounding the issue. I'll try to look at it soon enough. Santtus 15:12, 26 April 2006 (UTC)
 * You may want to edit the article on eye as well, because it states only the 100:1 figure. GreenGrass 14:58, 7 May 2006 (UTC)
 * Was in the middle of editing, but I couldn't finish my writing before getting a headache ;) I'll finish it later. I checked from various sources that 100:1 seems to be fine - it's the most often quoted value. Found some info on contrast sensitivity too, but it measures minimum noticeable contrast, not maximum. Now I just got one more question. How do you define maximum contrast a person can see? I'll try to find an answer for that.. Santtus 13:18, 9 May 2006 (UTC)
 * Well, as the performance of an eye is apparently limited by the performance of its lens, it should be easy to measure its static contrast ratio. You can fill 50% of your FoV with a white object, and 50% with a black object (with sufficiently high ratio between their diffuse reflectivity). Then you place a small text on the black object with a brightness just a bit more than the background. Afterwards, you gradually increase the brightness of the text until it becomes resolvable (in layman's words: "readable"). Than you measure the contrast ratio between the luminosity of the text and the luminosity of the white object, multiply it by two, and there you have it. (I took the last number from my head, it should be the minimum contrast necessary for the eye to detect edges of letters, which is probably a bit subjective issue). GreenGrass 19:55, 15 May 2006 (UTC)

Good article
Good job on the article. I would start working on correcting grammar & etting some pictures.

Extraordinary contrast ratio
It appears that the phrase "extraordinary contrast ratio" doesn't mean anything special, except that a someone feels that the contrast ratio is great. I've found no examples of professional use of that phrase, so I'll revert the changes unless I'm otherwise convinced. Santtus 09:12, 13 June 2006 (UTC)

Local contrast
The article should mention the difference between local and "global" contrast (both spatial). Local contrast means contrast near differences between luminances. For example, if there is a white box on a black background, local contrast is the contrast close to the border between the white and the black areas. Global contrast is a bit like dynamic contrast, except both bright and dark areas may exist simultaenously - contrast is measured where the differing luminances don't "contaminate" each other. CRT monitors may have infinite global contrast because of the ability to turn off the electron beam completely, but they have worse local contrast than LCD displays, because due to internal reflections bright areas have halos which contaminate the dark areas. ANSI contrast measures local contrast unless the checkerboard pattern is very sparse. Global contrast should still be differentiated from dynamic contrast, because for example even if you adjust the backlight of an LCD monitor to achieve a high dynamic contrast, it won't help you if you have bright and dark areas at the same time. The great thing (for CRTs!) is that out eyes have low local contrast and high global contrast. This is also exploited for LCD monitors that are backlit by LEDs. Since there are fewer LEDs than pixels, the local contrast is low, but the global contrast can be great. A local HiFi magazine measured each three contrasts for the televisions they reviewed. This online article also highlights the differences between local and global contrast (in the article they're called contrast and dynamic range respectively): http://www.displaymate.com/ShootOut_Part_1.htm As you can see, the CRT has a global contrast of ~18,000:1 compared to the LCD's ~600:1! But a 9x9 checkerboard pattern demolishes CRT's local contrast, reducing it to ~100:1, while the LCD retains ~600:1 —The preceding unsigned comment was added by 84.231.81.152 (talk • contribs).

Methods of measurement
This paragraph:

Many manufacturers of display devices favor the use of the full on/full off method of measurement, as it will effectively cancel the effect of the room completely, giving as high ratios as possible. Equal proportion of light will reflect from the display to the room and back in both measurements, as long as the room stays the same. This will inflate the light levels of both the "black" and the "white" measurements in the same proportion, unaffecting the black/white luminance ratio.

is simply not true! If Lw, Lb and Lr are the white, black and room luminosity, respectively, then Lw/Lb might be very different from (Lw+Lr)/(Lb+Lr). The reason manufacturer prefer this contrast measurement is that it might give them higher contrast, than say the ANSI contrast. See for example the CRT (global) contrast vs. LCD (global) contrast in the previous comment.

I would suggest the following phrasing: Many manufacturers of display devices favor the use of the full on/full off method of measurement, as it will give higher contrast ration over the ANSI contrast measurement method. previous comment by user:yuvalaviel

I wrote that paragraph with assuming otherwise unilluminated room, with Lr = 0. Now that could be mentioned.

Actually it has not been established what is the most usual level of illumination in the testing room. If there is absolutely no other light than that what reflects from the screen, then we can establish that a fraction f (0<f<1) of the light reflects from the screen to the room and back. Then Lw/Lr = (Lw * (1+f)) / (Lr * (1+f)).

Judging from overly inflated contrast ratio figures generally presented in the marketing literature, it doesn't seem believable that the manufacturers would have generally performed their tests in any significantly illuminated environments.

Perhaps someone can shed light on this situation? 62.220.237.65 23:04, 29 March 2007 (UTC)

Contrast Ratio as marketing spec
I'd like to see some mention of contrast ratio as a marketing term for LCD computer monitors. There seems to be quite a bit of emphasis on contrast ratio. Is it really significant and measured the same across manufacturers? --24.249.108.133 22:19, 13 April 2007 (UTC)

Agreed, I'd like to see this as well. The external link http://www.practical-home-theater-guide.com/contrast-ratio.html seems like a good source to cite for how the ratios are inflated and how salespeople can misrepresent their meaning.

With the development of LED backlit LCD displays, LCDs will have the potential to get much better black levels than previously possible (because the LEDs that are responsible for backlighting a given section of the screen can be dimmed or turned off completely when that section needs to be darker than is possible with the LEDs at full brightness). I know this is possible intuitively, but I am no LCD engineer and I don't know what this technology is/will be called. It's dynamic something, but dynamic contrast ratio is already taken. Any ideas if or how this concept should be added? --71.228.196.178 01:04, 15 November 2007 (UTC)

 * it's called "local dimming". the first hit on a google search is http://hometheatermag.com/gearworks/108gear2/ Kapland (talk) 11:12, 26 November 2009 (UTC)

The bit that is there at the moment seems very similar to http://ap.viewsonic.com/me/dcr/ 124.171.10.207 (talk) 08:10, 30 August 2008 (UTC)

Observation form CRT monitors
hmm, I have let the mention of "infinite contrast CRTs" to stay, but I'd wish to find a source to mention how it actually is. The monitors I've owned have shown visibly grey "black" level. For a reason or another, the contrast ratio was not being advertised in the time when LCD monitors where unavailable. When did they start measuring and advertising contrast ratios anyway? (forgot to sign) Santtus 22:02, 5 September 2007 (UTC)
 * The contrast ratio is nearly the same on all CRTs and it also depends on the settings, if you make the picture dark enough (but not toot dark), you can get very high contrast ratios. It also depends on room lighting, it is best for teh contrast if you use the monitor in a complete dark room. --MrBurns (talk) 13:45, 10 December 2008 (UTC)

Blown out?
"The trick for the display is to determine how much of the highlights may be unnoticeably blown out in a given image under the given ambient lighting conditions". Could someone please clarify this sentence? I don't understand what is meant by "blown out" in the article's context. Is there a less technical term for it, perhaps? —Preceding unsigned comment added by 98.221.120.172 (talk) 20:42, 18 October 2008 (UTC)

 * I'm pretty sure the author is referring to "blown out highlights", also called clipping (photography). --68.0.124.33 (talk) 05:08, 14 December 2008 (UTC)

Comparison
Could I ask someone for a better comparison with regard to what is a "good"/"desired" ratio, as to what is a "low-end"? For example; a link to a table of products showing their current ratios? -- Mjquin_id (talk) 19:37, 21 August 2009 (UTC)

Different Ways of Measuring Contrast Ratio
I'm here as a result of some confusion while comparing 2 monitors at NewEgg.com. One monitor has a Contrast Ratio of "2000:1 ASCR" while the other has "DC 2000:1(1000:1)"

What does this mean, and how can the wiki be edited to explain the difference ? —Preceding unsigned comment added by Jonny Quick (talk • contribs) 06:35, 4 September 2010 (UTC)

Copyvio
I added the copyvio template thinking it would just be a simple tag, but I see that I opened up a can of worms and right now and too tired to really go through the process. I noticed quite a bunch of text was copied word for word from a website that copyvio notwithstanding is not very reliable. B137 (talk) 04:02, 21 April 2015 (UTC)

poor status of article
1 "contrast ratio" mainly is a wide-spread pleonasm.

2 The International Lighting Vocabulary CIE S017/E:2011 states: contrast 1. in the perceptual sense: assessment of the difference in appearance of 2 or more parts of a field seen simultaneously or successively (hence: brightness contrast, lightness contrast,  colour contrast, simultaneous contrast, successive contrast, etc.)

2. in the physical sense: quantity intended to correlate with the perceived brightness contrast, usually defined by one of a number of formulae which involve the luminances of the stimuli considered: for example by the proportional variation in contrast near the luminance threshold, or by the ratio of luminances for much higher luminances

3 Contrast is often specified by the ratio of luminance levels, so this ratio should not be called "contrast ratio", because it rather is a luminance ratio.

4 There is no such thing as "luminosity" in display engineering and visual perception.

5 Contrast between two optical states is not limited to white (100% RGB) and black (0%). Why should this "cancel out the effect of the room and result in an ideal ratio"?

6 "Brightness, as it is most often used in marketing literature, refers to the emitted luminous intensity on screen, measured in candela per square metre (cd/m2). The higher the number, the brighter the screen."

Marketing publications are not the right guide to solid Wikipedia articles. "Brightness" is not the emitted "luminous intensity", "luminous intensity" is not quantified in candela per square metre (cd/m2),

7 The concerns listed above are not the only ones that make this article at least doubtful. Complete revision is recommended in order to avoid continued confusion of the readers.

panjasan (talk) 06:58, 11 August 2015 (UTC)

title: Talk:Contrast ratio