Talk:Nyquist–Shannon sampling theorem

From Wikipedia, the free encyclopedia
Jump to: navigation, search
          This article is of interest to the following WikiProjects:
WikiProject Telecommunications (Rated B-class)
WikiProject icon This article is within the scope of WikiProject Telecommunications, a collaborative effort to improve the coverage of Telecommunications on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
B-Class article B  This article has been rated as B-Class on the project's quality scale.
 ???  This article has not yet received a rating on the project's importance scale.
 
WikiProject Mathematics (Rated B-class, Mid-priority)
WikiProject Mathematics
This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
Mathematics rating:
B Class
Mid Priority
 Field: Analysis
One of the 500 most frequently viewed mathematics articles.
WikiProject Electronics (Rated B-class)
WikiProject icon This article is part of WikiProject Electronics, an attempt to provide a standard approach to writing articles about electronics on Wikipedia. If you would like to participate, you can choose to edit the article attached to this page, or visit the project page, where you can join the project and see a list of open tasks. Leave messages at the project talk page
B-Class article B  This article has been rated as B-Class on the project's quality scale.
 ???  This article has not yet received a rating on the project's importance scale.
 


the "technical" tag[edit]

The tag says

This article may be too technical for most readers to understand. Please help improve this article to make it understandable to non-experts, without removing the technical details. The talk page may contain suggestions.

So I am creating this place for suggestions. My own assessment is different. I think there are probably too many "technical details", such as critical frequency, non-baseband sampling, non-uniform sampling, undersampling, and multivariable sampling that could be relegated to the See Also list, if we need to make the article less intimidating. The actual discussion of the theorem itself has excellent illustrations and is (in my opinion) readily understandable to those with an understanding of the Fourier transform, which seems to be a universally accepted prerequisite. If the tagger is suggesting that we explain the sampling theorem without use of frequency domain concepts, that would be highly unconventional. Unfortunately, I think the Fourier transform article suffers much more than this one from technical overkill (from the non-experts' point of view). It would be a good candidate for a 2-pronged approach, meaning an experts' version and a dumbed down version for the rest of us. But that doesn't seem to be the way Wikipedia likes to do things.
--Bob K (talk) 11:49, 9 November 2013 (UTC)

The "2-pronged approach" is, in fact, the way Wikipedia articles should work, according to the WP:UPFRONT guideline: include highly technical information for experts -- but put it later in the article, *after* the up-front information for the rest of us. --DavidCary (talk) 03:41, 19 December 2013 (UTC)

Thanks. It looks to me like we've done that. So I don't have any suggestions to improve the article.--Bob K (talk) 15:46, 19 December 2013 (UTC)

I am having difficult time to understand this approach. It sounds absurd. It is a technical subject. What do you expect? This is an encyclopaedia article. Tutorials or further background material should be linked. I don't see any requirement of having technical articles in the level of layman in wikipedia. mcyp (talk) 09:14, 31 December 2013 (UTC)

Are you wishing to discuss WP:UPFRONT? The best place for that is probably Make_technical_articles_understandable. --Bob K (talk) 04:18, 1 January 2014 (UTC)

@Bob ; I totally agree that introductions should be well written and clear for general audience. But in some subjects, like this one, it is difficult to explain without using jargon and technical concepts. Thank you for the pointers. I will read first the guidelines. mcyp (talk) 04:15, 3 January 2014 (UTC)

Confusing: Shannon's version of the theorem[edit]

That there is a paragraph after the verbatim quote of Shannon's version of the theorem is testament to how confusing the original is, particularly with regard to what is meant by 1/2W.

Is it really necessary to include the confusing original text?

The use of 'cps' rather than Hertz, and W rather than B, confound things further.

Wootery (talk) 17:37, 28 August 2014 (UTC)

Looks like IP 71.169.182.71 has taken care of the W vs. B (and f(t) vs. x(t)) symbol confusion. I hope that edit sticks. 207.136.224.138 (talk) 18:00, 29 August 2014 (UTC)

References in "other discoverers"[edit]

Quoted text goes back to Meijering, for which http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=993400 ist given as URL. This, however, includes different references, so numbering is worng in wikipedia. And worthless as well, as the numbers are not explained/actual references given. 131.234.247.64 (talk) 07:18, 13 November 2014 (UTC)

White washing[edit]

"The name Nyquist–Shannon sampling theorem honors Harry Nyquist and Claude Shannon. The theorem was also discovered independently by E. T. Whittaker, by Vladimir Kotelnikov, and by others."

Well it wasn't discovered by "others" but 15 years earlier than anybody else by Kotelnikov in 1933. But not worth mentioning it right? Wikipedia rules!--2.242.113.76 (talk) 02:07, 17 April 2015 (UTC) --2.242.113.76 (talk) 02:07, 17 April 2015 (UTC)

The historical background section goes into a bit more detail on the various inventors/discoverers, dates, etc., and cites secondary sources about the history. I think the guy who really get shortchanged the most is Küpfmüller, 1928. Dicklyon (talk) 04:20, 17 April 2015 (UTC)

Contradiction in lede[edit]

The lede says "It establishes an upper limit on signal bandwidth or a lower limit on the sample rate that permits a discrete sequence of samples to capture all the information from a continuous-time signal." which suggests a necessary condition. It later says "The theorem does not preclude the possibility of perfect reconstruction under special circumstances that do not satisfy the sample-rate criterion." This seems like a confusion about whether the theorem gives a necessary condition, versus a sufficient condition. The body of the article suggests sufficient, so the lede paragraph probably needs to be edited to reflect that. 2620:0:1000:157D:84A4:C4BB:A81E:EA36 (talk) 16:28, 21 April 2015 (UTC)

I've copyedited the lead to be more precise. The discrepancy appears to be related to additional constraints on the signal that could be exploited in the reconstruction; the absence of known constraints on the signal other than bandwidth is necessary for the theorem to be applied in the sense of prescribing a necessary condition for perfect reconstruction. —Quondum 18:14, 21 April 2015 (UTC)
I made some more edits to make it more precise by avoid stating a converse, which is not true in general. 2620:0:1000:157D:FC67:567C:2428:191 (talk) 20:05, 22 April 2015 (UTC)
I like it. —Quondum 20:41, 22 April 2015 (UTC)