Driven by an local requirement, I have recently coded a Verhoeff decimal check digit program,
based on the Java calculator embedded in http://www.augustana.ab.ca/~mohrj/algorithms/checkdigit.html by Jonathon Mohr, [EMAIL PROTECTED] Augustana University College, 4901 - 46 Ave., Camrose, AB T4V 2R3 Canada For example, if you have a decimal number 1357, the Verhoeff check digit is 3 and if you enter the complete number 13573 incorrectly nearly all human errors, like transposition, will be detected. (But I note that this appears to give different results to the one in Numeric Recipes in C++ - someone wrote about this on Boost recently - which references the same sources, mainly Neal AR Wagner and Paul S Putter, Comm of the ACM, 32(1) 106 to 110, and the original but difficult to obtain paper by J M Verhoeff). This is by far the best human error detecting check digit scheme and would seem to be a good candidate for a Boost library (though ISBN, credit card and US EFT schemes could also be made available though they are not recommended for new applications). Two questions: 1 Is there any interest in these schemes? Which? 2 It would be valuable to generalise this to other more compact number systems, for example ones based on 16 (familiar Hexadecimal) and 32 (letters and numbers). (I have recently opened a bank account with a 13 decimal digit identifier! This could be as little as 5 with a 32 character letters and numbers scheme.) The Deutsche Bundesbank bank notes are numbered using letters as well as numbers and use a extended Verhoeff check digit scheme. Does anyone have any details, especially programs, showing how this works? Or does anyone know of other extensions to other number & letter schemes? Thanks Paul Paul A Bristow, Prizet Farmhouse, Kendal, Cumbria, LA8 8AB UK +44 1539 561830 Mobile +44 7714 33 02 04 Mobile mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] Numerical Recipes in C++, p 904 - 905W H Press, S A Teukolsky, W T Vettering, B P Flannery, ISBN 0 521 75033 4. SNOMEDŽ Clinical Terms (First Release Technical Reference Manual First Release (January 2002), Annex B. Check-digit computation, p 30 to 34 http://www.snomed.org/Spanish%20Documents/SNOMEDCT_Core_Technical%20Reference%20 Manual_US.pdf uses Jonathan Mohr Javascript checkdigit.htm (copy in checkdigit.txt) based on code at http://www.augustana. ab.ca/~mohrj/algorithms/checkdigit.html _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
