Talk:Check digit

From Wikipedia, the free encyclopedia
Jump to: navigation, search
WikiProject Computing (Rated Start-class)
WikiProject icon This article is within the scope of WikiProject Computing, a collaborative effort to improve the coverage of computers, computing, and information technology 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.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 ???  This article has not yet received a rating on the project's importance scale.
 
WikiProject Computer science (Rated Start-class, Mid-importance)
WikiProject icon This article is within the scope of WikiProject Computer science, a collaborative effort to improve the coverage of Computer science related articles 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.
Start-Class article Start  This article has been rated as Start-Class on the project's quality scale.
 Mid  This article has been rated as Mid-importance on the project's importance scale.
 

Still to be added is a discussion of the Verhoeff check digit scheme. See the marist.edu link.

16:06, 7 February 2006 (UTC)69.74.32.122 16:06, 7 February 2006 (UTC) I agree. Verhoeff is a little in depth (not too much though). And there are a few ways to calculate a Verhoeff check which all have a similar effect. The biggest difference is the σ (sigma) function. I've encountered two commonly used functions to transform digits in addition to the universally used dihedral group transformation.

Daniel 16:06, 7 February 2006 (UTC)69.74.32.122 16:06, 7 February 2006 (UTC)

This page contains errors[edit]

I'm sorry that I do not have time to correct this page, but there are several major errors:

In the ISBN example the weights are applied from the left most digit, starting with a weight of 1. Weights should be applied from the RIGHTMOST digit, starting with a weight of 2. This is because the check digit actually assumes a weight of 1, and is in fact the complement of the modulo 11 arithmetic remainder (i.e. 134 modulo 11 = 12 R 1, so the check digit is 11 - 2 = 9). When the ISBN code is checked for integrity the whole code, including the check digit, is used in the calculation and will produce an answer of 0 if valid.

The algorithm at the bottom of the article does not work, unfortunately I csnnot immediately see what it should be. —The preceding unsigned comment was added by 210.3.39.30 (talk) 02:46, 15 February 2007 (UTC).

Control number[edit]

Is this the same as a control number?


Not completly, I think a control number can be a more complex than just a check digit. See here: http://glossary.ippaper.com/default.asp?req=knowledge/article/211 Gs1mo 21:00, 16 May 2007 (UTC)

Another example of check digits[edit]

International Bank Account Numbers also contain check digits?

UK VAT numbers also have check numbers and this can be a way of cehcikng the bone fides of a company, perhaps someone who knows it could add it here?85.234.151.89 (talk) 19:07, 19 December 2009 (UTC)

Orphaned References[edit]

Contemporary Abstract Algebra by Joseph Gallian, 5th edition, Houghton Mifflin, 2002, pp. 9-14.

"Modular Arithmetic in the Marketplace", by Joseph Gallian and Steven Winters, in The American Mathematical Monthly, Vol. 95, No. 6, 1988, pp. 548-551.

I don't see where these were being used in the article. I added a reference to EAN-13 check digit computation to the article. I also found a reference to the documentation for ISBN-10 check digit computation, but it is not public domain so I did not add this reference to the article at this time: http://www.lac-bac.gc.ca/iso/tc46sc9/2108.htm Calebb (talk) 07:28, 22 May 2008 (UTC)