The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.

The result was redirect to Covariance matrix. Content may be merged from history. Sandstein 11:36, 26 September 2018 (UTC)[reply]

Covariance mapping[edit]

Covariance mapping (edit | talk | history | protect | delete | links | watch | logs | views) – (View log · Stats)

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A few sentences of mathematical triviality (generalizes the notion of covariance from random variables to random functions) are followed by an unencyclopedically detailed account of a free-electron-laser experiment. This is nothing but advertisement for a few papers by a small group of scientists. Relevance of their work is not demonstrated. Nsda (talk) 09:17, 19 September 2018 (UTC)[reply]

Note: This discussion has been included in the list of Mathematics-related deletion discussions. XOR'easter (talk) 16:13, 19 September 2018 (UTC)[reply]

• Delete as per explanation by nominator: mathematical title, but no notable mathematics; extreme detail on physics experiment is unencyclopedic. Also, content seems to have been written by same person who is author or co-author of all six cited works, hence WP:COI. Loraof (talk) 15:14, 20 September 2018 (UTC)[reply]
• Delete Isn't this just the covariance matrix? Their definition is ${\displaystyle \mathbf {cov} (\mathbf {Y} ,\mathbf {X} )=\langle \mathbf {YX} \rangle -\langle \mathbf {Y} \rangle \langle \mathbf {X} \rangle ,}$ with ${\displaystyle \mathbf {Y} }$ the transpose of the row vector ${\displaystyle \mathbf {X} }$. So the ${\displaystyle (i,j)}$-th entry in their matrix is ${\displaystyle \langle x_{i}x_{j}\rangle -\langle x_{i}\rangle \langle x_{j}\rangle }$. In addition, chunks of the content were copied from this article, which is Open Access but uses a different license than Wikipedia does. I think this is technically disallowed under our copyright policy (the attribution is lost, for one thing), and it certainly intensifies the WP:COI concerns. XOR'easter (talk) 16:49, 20 September 2018 (UTC)[reply]

It's published under CC-BY-3.0, which is compatible with Wikipedia's licence (Wikipedia:Copying text from other sources#Can I copy from open license or public domain sources?), given suitable attribution (Wikipedia:Adding open license text to Wikipedia#Attributing text). Qwfp (talk) 19:35, 20 September 2018 (UTC)[reply]

• Very selective page merge to 'Covariance matrix'. As XOR'easter points out, this appears to be just an application of the covariance matrix to a discretised function. A Google Scholar search for "Covariance mapping" -wikipedia -"Frasinski" brings up enough articles by other authors to suggest the term is sufficiently used to be worth at least a mention at 'Covariance matrix', but i agree with the nominator that the nominated article is too detailed and too focussed on one specific application and one group's papers for very much of it to be useful. Qwfp (talk) 19:35, 20 September 2018 (UTC)[reply]

Note: This discussion has been included in the list of Science-related deletion discussions. XOR'easter (talk) 23:09, 20 September 2018 (UTC)[reply]

I could agree with that, but who will carry it out? Waiting for a volunteer should not delay the deletion of the present, inappropriate article. Nsda (talk) 08:34, 21 September 2018 (UTC)[reply]

We could make the page into a redirect first and worry about merging bits of it later. (I'm not seeing much that compels merging, but if there aren't copyright issues then we don't have to expunge the page history from public view.) XOR'easter (talk) 15:06, 21 September 2018 (UTC)[reply]

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.