Talk:Projection-slice theorem: Difference between revisions

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Revision as of 15:28, 7 October 2019

Cleanup

This article is a bit of a dog's dinner at the moment. The first part is too informal in style for an encyclopaedia, and the brief explanation of the theory is better in Radon transform. I am going to try to do a bit of tidyingBilllion (talk) 19:05, 6 April 2011 (UTC)[reply]

I think this article doesn't need a cleanup anymore and I removed the note. Any objections to this? Gromobir (talk) 19:43, 11 October 2014 (UTC)[reply]

Misleading Figure

The figure is confusing. It illustrates that the projection is taken along the x direction, but the text reads that it is a projection onto the x-axis. It technically is not a projection onto the x-axis since there is no particular location to which the projection belongs. I suggest removing the figure until a better one is made. hovden (talk) 14 June 2018 —Preceding undated comment added 14:51, 14 June 2018 (UTC)[reply]

Misleading Use of term "Projection"

I came across this page hoping to find some quick information on the scope of the projection-slice theorem. Unfortunately it doesn't help much. The use of "projection", combined with the link to Projection (mathematics) as the only definition of projection, is seriously misleading. Projection (mathematics) defines a projection as any idempotent mapping, however that is clearly not the definition used in this theorem: it is not valid, for example, for min or max projections, though it's possible there might be other transforms they could combine with to give a valid theorem. It means that the page is only useful to people who already know most of the theory (in particular, which specific projections the theorem covers - unfortunately that doesn't include me). I don't know the theory well enough to edit it, because I don't know how to delineate exactly which projections and transforms it does hold for - clearly integral projections, but is it valid for any other projections, maybe in conjunction with other transforms? For example, I think it probably holds for sum projections and DCTs, and there might well be Boolean analogues. Could someone who does know the theory well enough please clarify this. If it only holds for integral projections (or if other transforms are required for other projections) please say so. Thanks for any help. Urilarim (talk) 05:48, 22 June 2018 (UTC)[reply]

Overview Figure

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I uploaded a nice overview figure on Wikimedia Commons that is available under CC 4.0 BY. I think, it explains the concept very well and would nicely fit this article. Please decide whether you think it is an appropriate addition.

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 == Overview Figure ==
-I found a nice overview figure on Wikimedia Commons. I think, it explains the concept very well and would nicely fit this article:
+{{requestedit}}I uploaded a nice overview figure on Wikimedia Commons that is available under CC 4.0 BY. I think, it explains the concept very well and would nicely fit this article. Please decide whether you think it is an appropriate addition.
 [[File:Fourier Slice Theorem.png|thumb|Fourier Slice Theorem]]