User talk:David Eppstein

Hi, and welcome to my User Talk page! For new discussions, I prefer you add your comments at the very bottom and use a section heading (e.g., by using the "+" tab at the top of this page). I will respond on this page unless specifically requested otherwise.

Geometric Progression

Don't know quite who is the general custodian of this page but technically in the summation formula you should run from k=1 to k=n and not from k=0 to k=n. The nth term is customarily ar^n-1 and not arⁿ. So the summation formula should read $S_{n}={\frac {a(r^{n}-1)}{r-1}}$ or alternatively ${\frac {a(1-r^{n})}{1-r}}$. In the derivation of this formula the final term in the sequence is ar^n-1 and not arⁿ.

Neil Parker (talk) 14:53, 30 June 2010 (UTC)

There's nothing wrong with summing n+1 terms instead of n, and making the exponent on the last term be n instead of n−1. It's just a trivial change of variable. —David Eppstein (talk) 15:09, 30 June 2010 (UTC)

It is of course not technically wrong at all. You could always (equally trivially) sum n+101 terms and make the last term's exponent be n+100 if you like. But with due respect this is supposed to be a general purpose encyclopedia and therefore as far as possible should abide by well established convention in which arithmetic/geometric sequences are defined over n terms beginning with n=1. With T_n=a+(n-1)d and ar^n-1 respectively to ensure the first term in both cases is just a. And then we sum n terms - not n+1 terms. Sorry to 'nitpick' but I think it's a point that ought to be made.

Neil Parker (talk) 11:37, 1 July 2010 (UTC)

You are assuming that n means "the number of terms". With that assumption, the convention you describe makes sense. But n could equally well be interpreted to mean "the exponent of the last term". With that assumption, the other convention makes sense. I don't know of a natural meaning for n that would make sense of having n+101 terms ending at an exponent of n+100. —David Eppstein (talk) 16:03, 1 July 2010 (UTC)

A fundamental definition of the term finite sequence is a function whose domain is the set of positive integers {1,2,3...n}. So we start the sequence at position 1 and we end at position n. And by this definition n is indeed the number of terms in the sequence. Notation such as T_n= ... or S_n=... relies on this definition and will undoubtedly become ambiguous if we start inventing alternate interpretations of n however 'natural' they may be.

Neil Parker (talk) 16:06, 7 July 2010 (UTC)

I think it's more common in higher mathematics to start at 0, actually. But, more importantly, this is NOT a definition: it's just a convention. —David Eppstein (talk) 16:40, 7 July 2010 (UTC)

Convention or definition? Fundamental to the concept is the idea that you have a set of tangible discrete elements and when you count tangible discrete elements (sheep, pencils, people or whatever) you start at 1 which is the common sense rationale for mathematically defining a sequence over the set of positive integers.

Neil Parker (talk) 18:39, 8 July 2010 (UTC)

Fortune's algorithm

Thanks for reverting! I realised overnight that there are two different projections in play. Came in this morning to revert, but found you'd got there first.

Fortune's paper uses an oblique projection that transforms the edges in the Voronoi diagram into hyperbolae. This treatment – an orthogonal projection of the parabola representing equidistance from scan line and a site, which projects the Voronoi edge hyperbolae to lines – is clearer. Michael Fourman (talk) 10:27, 2 July 2010 (UTC)

That's the way it's described in the Dutch book. Sometimes I forget that the original paper did it a little differently. —David Eppstein (talk) 16:22, 2 July 2010 (UTC)

You might be interested

You voted in this AfD. It was closed in six days, than the minimum seven. The article was re-created (though not by me), and was tagged with a speedy. I have contested the speedy, while not removing it myself. Just thought I'll leave a note for reference. ♪ ♫ Wifione ♫ ♪ _―Œ ^{♣Łeave Ξ мessage♣} 09:08, 5 July 2010 (UTC) ♪ ♫ Wifione ♫ ♪ _―Œ ^{♣Łeave Ξ мessage♣}

Please arbitrate my allegation of wikihounding

Since you are an administrator, I ask that you arbitrate my allegation that Arthur Rubin is harassing me with destructive reversions. While I recognize that much of the reverting he does is legitimate enforcement of Wikipedia rules, it seems that in many cases (not just mine--see his talk page and its archives) he is hampering people's legitimate efforts. I am an editor with hundreds of constructive edits, and not some fringe crackpot.

My specific complaints are outlined on his talk page in a 5 July 2010 entry. I ask that you consider a temporary block on him as a warning.

If you are unwilling to arbitrate or feel that you have a conflict of interest (having sided with him or against him in the past), please pass this request along to a neutral arbitrator.

Thanks very much. Duoduoduo (talk) 17:20, 5 July 2010 (UTC)

I only see three reversions of your edits among his last 50, and they all look like appropriate removals of inane wikilinks to me. I don't think this is wikihounding, and I don't think it needs any administrative attention. I think you should take this episode as constructive criticism and think seriously about making your edits be more useful rather than whining about being unappreciated. I'm not going to pass your request along, I'm certainly not going to block him over this, and if I see you making such requests elsewhere I'm going to come out against them. —David Eppstein (talk) 17:27, 5 July 2010 (UTC)

Okay, so you won't. But did you even look at my reasoning on his talk page? I challenge you to explain why any of my links that he reverted are "inane", as you put it. For example, please explain why linking "quintic equation" to "sextic equation" is inane.

Also, please show me where I was "whining about being unappreciated"—I don't recall that. In fact I believe I am appreciated on Wikipedia. Please be civil. Duoduoduo (talk) 18:14, 5 July 2010 (UTC)

BINGO

You left out Bo Jacoby (!). What do I win? Sławomir Biały (talk) 00:27, 12 July 2010 (UTC)

I guess I haven't had the misfortune to encounter him often enough to remember. —David Eppstein (talk) 00:29, 12 July 2010 (UTC)

Graph style

Hello. To avoid copyvio issues with MathWorld, I have changed the style of my graphs: [1] I have also redrawn a few of them. For the large graphs with low-order LCF notations, I have chosen new Hamiltonian cycles.

In fact, Wikipedia will be prettier if all the graphs use the same style. Now can I change the style of your graphs? I have done it on File:Goldner-Harary graph.svg (as an example).

I have also added some sources for my layouts. If there are remaining problems with copyright, please, let it know. Koko90 (talk) 13:00, 13 July 2010 (UTC)

Recoloring the vertices doesn't particularly bother me, in the cases where the colors aren't already meaningful, if that's what you mean. I don't think I'd want the ones where I'm already using multiple colors to highlight some features of the graph (such as File:Branch-decomposition.svg) to be recolored. —David Eppstein (talk) 15:11, 13 July 2010 (UTC)

Of course. Koko90 (talk) 17:36, 13 July 2010 (UTC)

Please undelete 'Elaine Mardis' article

Hi, I am new to Wikipedia and didn't know I couldn't reuse my own material on this site. I believe this is why you deleted my article on 'Elaine Mardis.' Would you mind restoring the article and I will rewrite it so it no longer contains copyright issues? Many thanks, --Gremerow (talk) 13:42, 26 July 2010 (UTC)

I'd rather not restore copyright-violating content, but it seems I don't have to: it appears to be the same as what's currently on your userpage. —David Eppstein (talk) 15:40, 26 July 2010 (UTC)

Yes, I've restored the material myself so it no longer violates copyright - can you tell me if it will still be targeted for deletion? Thanks, --Gremerow (talk) 22:11, 26 July 2010 (UTC)

It looks ok to me. The US News and CBS News cites look like enough for notability, and her citation record in Google scholar looks well more than enough for WP:PROF. Some of the basic factual information in the article (her education and current and previous positions) could use citations to third-party sources, though.

Added additional citations/references. Thanks, --Gremerow (talk) 19:54, 27 July 2010 (UTC)

Would you close this AFD? (Siemens PLM Software)

This AFD was opened more than a month ago and hasn't been commented upon since July 9th. The consensus looks pretty clear to me. Would you consider closing this AFD? (I would close it myself if I had not voted on it.) Thanks--Justin W Smith ^talk/_stalk 23:29, 26 July 2010 (UTC)

 Done —David Eppstein (talk) 23:57, 26 July 2010 (UTC)

Wikipedia:Articles for deletion/Elaine Mardis

When you closed this discussion you only dealt with the one article. The AfD mentioned two other articles (George Weinstock and Timothy Ley) and although it's debatable whether they should have been added to the AfD they are still AfD tagged with the tag pointing at this discussion so some clean up is necessary. As closer of this AfD I was wondering if you'd be so good as to look into it and tidy it up. Cheers. Dpmuk (talk) 12:28, 27 July 2010 (UTC)

It seems that the copyright problems on all three articles have been resolved. —David Eppstein (talk) 16:16, 27 July 2010 (UTC)

Yep, it would appear they got resolved a couple of hours after I left you a message but I haven't been around on Wikipedia to notice and let you know. Dpmuk (talk) 21:35, 27 July 2010 (UTC)

Incompleteness talk page

Thanks for moving the thread I started there. I had thought about it moving it myself (or archiving it), but I hesitated to move it before other people had a chance to respond. The argument was devolving, as you pointed out, to the same argumentative historical revisionism as before. — Carl (CBM · talk) 13:51, 31 July 2010 (UTC)

Talk:Gödel's_incompleteness_theorems

Could you please not semi-protect that page? I've been posting to it for a long time, and there are lots of good editors working in math articles from IP addresses in general. Just revert any edits that appear to contravene the Hewitt ban, and block any IP's that make those edits. 67.122.211.208 (talk) 02:26, 3 August 2010 (UTC)

Is there a reason you can't make a login for yourself? —David Eppstein (talk) 02:41, 3 August 2010 (UTC)

I had one a long time ago but I quit using it. I'm a much happier editor this way so I have no interest in turning back. 67.122.211.208 (talk) 03:06, 3 August 2010 (UTC)

I can vouch that we've have one longstanding IP editor from San Francisco (formerly this IP). Unfortunately most of the Hewitt socks are in California as well. My personal preference, at least slightly, is to just be more proactive in moving comments to the arguments page. — Carl (CBM · talk) 02:05, 4 August 2010 (UTC)

Ok, given both of your requests to do so I've unprotected the talk page again. —David Eppstein (talk) 02:22, 4 August 2010 (UTC)

Thanks. The situation isn't really good either way. Maybe it will improve when the school year starts. If it gets worse, I will not argue against protection. I'm on the fence as it is. — Carl (CBM · talk) 16:03, 4 August 2010 (UTC)

Yes, the editor CBM linked to (and 67.122.211.208) are both me. I don't understand why either of you have a problem treating ban evaders in the traditional fashion per WP:BAN: revert and block on sight. I realize that Hewitt has done some worthwhile stuff as a CS academic but on Wikipedia he and his socks are simply unredeemable abusers and spammers. It may just be that in mathematical logic Hewitt's activities are no more than a nuisance, but in computer science things are much worse. They have made sizeable swaths of Wikipedia unreliable. Anything having to do with actor languages or Scheme needs massive rewriting and cleanup that will probably never happen, so they will stay full of Hewitt's self-aggrandizement and revisionism. Please also see this discussion proposing a fullscale ban, also initiated by me, but which didn't go anywhere. 75.62.4.94 (talk) 07:11, 8 August 2010 (UTC)

PS: if of any interest, Hewitt has moved some of his antics over to Lambda the Ultimate (theory-oriented programming language blog): [2]. I guess they'll figure out his game sooner or later. 75.62.4.94 (talk) 07:16, 8 August 2010 (UTC)

Mahinda Pathegama

Hi David, I am little taken aback by the comments left by an editor against me in the above article. This the first time such an accusation has made against me. Well, I am not from the UK, I live in Sri Lanka and I have no association whatsoever with this professor or any of the contributors to the article. As you might have noticed there clearly we have two camps here, Pathegama-praisers and Pathegama-attackers. As an independent Wikipedian who has been here for two and a half years, I won't bow down both parties' personnel attacks or POV of their opinion on the subject. Thinking of Keep !voting in the AfD. Hope you can assist me on the personnel attacks and vouch for my identity as a genuine, NPOV Wikipedian. Regards--Chanaka L (talk) 05:18, 4 August 2010 (UTC)

Wikipedia:Articles for deletion/Luboš Motl (3rd nomination)

Dear David I have looked up Motl on both Web of science and Scopus. Web of science calculates a h-index of 8 and total citations of 419 for the 12 articles. Scopus also yields a h-index of 8 - these seem a lot different from your figures. Do you know what I might be doing wrong or what the explanation might be? Best wishes (Msrasnw (talk) 01:54, 6 August 2010 (UTC))

It could be simply a matter of using an index that only looks at dead trees and not at the arxiv, where as I understand it all high energy physics research is done these days. I did only the most basic Google Scholar search by author [3]. Note, for instance, that his most highly cited paper in GS ("Proposals on nonperturbative superstring interactions", nearly 300 citations) exists only as an arxiv paper and not in journal form. —David Eppstein (talk) 02:14, 6 August 2010 (UTC)

Many thanks (Msrasnw (talk) 02:31, 6 August 2010 (UTC))

photo of Little River

Thanks for the photo!—Stepheng3 (talk) 16:03, 17 August 2010 (UTC)

You're welcome! I added a few more of some other nearby spots. But the weather in the Mendocino area wasn't good for photography, this visit, or I would have taken more. —David Eppstein (talk) 21:59, 22 August 2010 (UTC)

Metric dimension

Based upon Deza & Deza, I made Metric dimension a disambiguation page. It previously redirected to Metric dimension (graph theory), but clearly the term has several disparate meanings. I only linked it to two other pages, but I'm sure several more should be added. Justin W Smith ^talk/_stalk 22:56, 18 August 2010 (UTC)

Yes, that sounds like the right way to handle it. —David Eppstein (talk) 22:57, 18 August 2010 (UTC)

DYK for Konocti Harbor

Courcelles 00:04, 19 August 2010 (UTC)

I see you've been busy

I see from my watchlist that you've been busy improving a bunch of California geography articles. This is one of my areas of interest, and I'm pleased with your contributions. Thank you and please keep up the good work. Cheers! --Stepheng3 (talk) 21:29, 22 August 2010 (UTC)

You're welcome! I just returned from a long road trip to northern California, and that generally perks my interest in the subject. —David Eppstein (talk) 21:32, 22 August 2010 (UTC)

John C. Wright (author)

Thanks for your contributions to protect this BLP. Off2riorob (talk) 22:46, 26 August 2010 (UTC)

Shibley Rahman

You obviously have a lot of experience, but I just simply feel you are wrong.

You haven't addressed any of my points, especially you choose to ignore that the Brain paper is cited as a key reference in the current edition of the 'Oxford Textbook of Medicine' which is one of the world's most prestigious textbooks for all physicians. Consultants and Professors even use it.

I have written this below elsewhere but please do not take any of it personally.

Regards though.

A person has written

Delete. I see no evidence that he passes WP:PROF, and the article has few or no reliable sources that are actually about its subject. —David Eppstein (talk) 20:31, 28 August 2010 (UTC)

CLEARLY the person has not read any of the above. H If you do a Google search on "quality of life" or "Freezing of gait" for the Parkinson's disease articles, also using "Rahman" "Griffin" and "Jahanshahi", you'll find all the papers cited in the Google Search. Going to the actual papers will then tell you how the paper has been specifically discussed.

Furthermore, for "frontotemporal dementia", "Rahman", "Hodges", and try any of the papers cited in the references, you will find the papers discussed in the actual papers.

As I said, many of them are international reviews not done by Rahman.

Your person above, David Eppstein, has FAILED.

And he should NOT ignore the fact that the Brain study has been cited in one of the world's leading reference for medicine.

I find therefore the manner of Eppstein's remark INCORRECT.

In his communication, I find no evidence that he has addressed any of the points in the discussion above, which is clearly wrong.

Articleman11 (talk) 18:34, 28 August 2010 (UTC)Articleman11

I didn't as such answer your question, David. I am disabled,

The person's research has made significant impact in their scholarly discipline, broadly construed, as demonstrated by independent reliable sources.

This research has made a huge impact for a decade. It is a massively cited paper, and a lot of the papers in the article themselves are independent reviews of the work in book chapters or journal reviews

The person has received a highly prestigious academic award or honor at a national or international level.

Dr Rahman received an academic scholarship at Cambridge which is one of the UK's top universities.

The person is or has been an elected member of a highly selective and prestigious scholarly society or association (e.g. a National Academy of Sciences or the Royal Society) or a Fellow of a major scholarly society for which that is a highly selective honor (e.g. the IEEE)

Dr Rahman has been elected a Fellow of the Royal Society for Encouragement in the Arts, Commerce and Enterpreneurship; and been elected as a Member of the Society of Biology. . The person has made substantial impact outside academia in their academic capacity.

I posted some of the details of http://www.lawandmedicine.wordpress.com., http://www.twitter.com/lawandmedicine, http://www.facebook.com/pages/Law-and-Medicine-Limited/256834847084?ref=ts, http://www.facebook.com/group.php?gid=153399719297&ref=ts, and I have a Wellcome Trust grant currently under review for a series of podcasts.

SR has therefore attempt to make an impact in law and medicine outside a formal academic setting. Furthermore, whilst disabled, he chose to work unpaid for a year in the information department of a medical charity, given my knowledge of medicine (this also has been deleted by one of the moderators completely unhelpfully: but the evidence he can't delete is here: http://www.linkedin.com/in/drshibleyrahman )

Please note that a friend of mine Daniel Hahn has a stub more or less, and his profile is there nonetheless. Please apply your standards FAIRLY AND CONSISTENTLY!

Articleman11 (talk) 18:34, 28 August 2010 (UTC)Articleman11

he research discussed fairly, with reference to many other international groups other than Cambridge, is cutting edge research in Cambridge. It is hard to know how you assess notifiability, the success of an academic, and these numbers will mean more to you than me, However, clearly a paper which has been cited 250 times by other journals (if that what it means) does merit coverage in a non-specialist source such as Wikipedia, if the whole aim of Wikipedia is to intend to educate? I think in all these rules you've lost sight of the actual purpose of Wikipedia, as explained in fact by your CEO.

I looked up the Rahman papers on Google scholar

Specific cognitive deficits in mild frontal variant frontotemporal dementia oxfordjournals.org [HTML] S Rahman, BJ Sahakian, JR Hodges, RD Rogers, TW … - Brain, 1999 - Oxford Univ Press Cited by 214 - Related articles - BL Direct - All 7 versions

Paroxetine does not improve symptoms and impairs cognition in frontotemporal dementia: a double-blind randomized controlled trial JB Deakin, S Rahman, PJ Nestor, JR Hodges, BJ … - …, 2004 - Springer Cited by 74 - Related articles - BL Direct - All 7 versions

Methylphenidate ('Ritalin') can ameliorate abnormal risk-taking behavior in the frontal variant of frontotemporal dementia

S Rahman, TW Robbins, JR Hodges, MA … - …, 2005 - nature.com Cited by 27 - Related articles - BL Direct - All 10 versions

Quality of life in Parkinson's disease: the relative importance of the symptoms hi.is [PDF] S Rahman, HJ Griffin, NP Quinn, M … - Movement …, 2008 – Cited by 46 - Related articles - All 8 versions

The factors that induce or overcome freezing of gait in Parkinson's disease S Rahman, HJ Griffin, NP Quinn, M Jahanshahi - Behavioural neurology, 2008 - Cited by 5 - Related articles - All 2 versions

Articleman11 (talk) 18:34, 28 August 2010 (UTC)Articleman11

I don't suppose it's ever occurred to you that the longer and more rambly and more argumentative you are, the less persuasive you are? —David Eppstein (talk) 22:31, 28 August 2010 (UTC)

That was simply rude AND YOU DID NOT ANSWER THE QUESTION. Do not be offensive, please. ANSWER THE QUESTION!!

Whilst I'm on the point, where exactly am I touting myself as a university academic? Is Wikipedia suddenly anti-intellectual? I am clearly described as having an interest in education and teaching.

I am not pretending to be an ACADEMIC,

Articleman11 (talk) 18:34, 28 August 2010 (UTC)Articleman11

DYK for Ten Mile River (California)

— Rlevse • Talk • 00:03, 30 August 2010 (UTC)

DYK for Randolph Blackwell

— Rlevse • Talk • 06:03, 30 August 2010 (UTC)

Latin America

Hello,

I contact you to request mediation with the user User:AlexCovarrubias, I make a change in the Latin America article citing references that verify the changes. But the user User:AlexCovarrubias reverts my edition, wanting to have another version with an outdated reference and not prior to that I provide.

You can see the same thing in the edit history. This topic was much discussed in the Spanish Wikipedia, being correct these references.

Thanks you! --Maxpana3 (talk) 18:53, 30 August 2010 (UTC)

DYK for Albion River Bridge

— Rlevse • Talk • 18:04, 31 August 2010 (UTC)

Tate Publishing

You started an RSN thread about Tate Publishing & Enterprises last year. I've started a new thread about one of their publications. Wikipedia:Reliable sources/Noticeboard#Tate Publishing: The Father of Hollywood.   Will Beback  talk  22:45, 1 September 2010 (UTC)

Wikipedia:Reliable sources/Noticeboard Tate Publishing

I would like it if you look at the page again and reevaluate what you posted. I hope you will take time to look at all the links I included. Perhaps you did not know the history of H J Whitley. Thanks for your help. Whithj (talk) 02:21, 2 September 2010 (UTC)

Duality

Keep in mind though there is a difference between accessibility and an intro which is vague. Regards.-Stevertigo (t | log | c) 04:43, 2 September 2010 (UTC)

Sure. But the starting sentence you chose instead, "Generally speaking, a duality translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one-to-one fashion, often (but not always) by means of an involution operation: if the dual of A is B, then the dual of B is A.", is neither. It doesn't give any idea that the subject is mathematics and the use of technical language such as involution makes it unreadable to anyone who isn't already familiar with mathematics. —David Eppstein (talk) 05:02, 2 September 2010 (UTC)

Note, I didn't actually rewrite the paragraph - I simply switched the placement of the first and second. I would have exceeded my limitations to rewrite the paragraph, but the concept "generally speaking" does get to the gist: Articles can and should get to the gist of a subject before getting into caveats. For example at the matter article, there are specialistic conceptions which contradict each other, still we are required to say something like 'matter == physical objects that have mass and volume.' The other problem with noting the caveats early is that often theres no attempt to explain exactly what those caveats are until much later. Regards, -Stevertigo (t | log | c) 05:56, 2 September 2010 (UTC)

John C. Wright (author)

Tanks for protecting that. I had asked at the RFPP page and have closed that now your have done it. Semi protection would have worked for the article but we presently are not able to add or request it, regards. Off2riorob (talk) 22:15, 5 September 2010 (UTC)

You're welcome. I did only semi-protect it, I think. At least, if I protected at a higher level than that, it wasn't intentional. —David Eppstein (talk) 22:32, 5 September 2010 (UTC)

Unexplained deletion to LiveJournal

Please do not remove content or templates from pages on Wikipedia, as you did to LiveJournal, without giving a valid reason for the removal in the edit summary. Your content removal does not appear constructive, and has been reverted. Please make use of the sandbox if you'd like to experiment with test edits. Thank you.Andy Dingley (talk) 00:48, 8 September 2010 (UTC)

Rather than responding in kind to your failure to read edit summaries, maybe I should just point you to WP:POINT. —David Eppstein (talk) 01:00, 8 September 2010 (UTC)

new user

Fyi: [4]

75.57.241.73 (talk) 06:37, 8 September 2010 (UTC)

David, some of that user's edits surprise me. Could you contact RJL offline and confirm this is not a hoax? Thanks. 75.57.241.73 (talk) 08:47, 8 September 2010 (UTC)

Turns out your suspicions are justified. I contacted the real RJL and he said it's not him. So I blocked the account for violating our user name policy (it's not ok to impersonate someone else). —David Eppstein (talk) 16:37, 8 September 2010 (UTC)

Thanks. I think you should mention this block on ANI (or I can do it for you if you want), since the person may return with other subtle mischief. 75.57.241.73 (talk) 20:06, 8 September 2010 (UTC)