On Thu, Aug 12, 2010 at 9:05 PM, RussellMc wrote: >> > What I am saying is that right shifting by 1/(2**N) loses N bits of >> > precision, > >> Actually we were talking about right shifting by N, which is the same as >> dividing by 2**N or multiplying by 1/(2**N). =A0Right shifting by 1/(2**= N) >> makes no sense at all. > > I think it's probably a matter of nomenclature - I've little doubt > that both commentators have a good grasp of what is involved. > > I'd read "right shifting by 1/(2**N) ... " as a short hand way of > saying that 'you achieve division by a factor of 2^N by right shifting > N bits, thereby losing N bits of precision, unless you use include an > underflow register in your algorithm'. Among consenting experts in PIC > who both know what the other guy knows I'd expect such dense compound > meanings to be well enough understood. But, I may be wrong :-). > > > =A0 =A0Russell Olin is technically correct (the best kind of correct). Right shifting by N is what I meant. My note about precision was not for experts like Olin, but to point out a trap for young players. Regards, Mark markrages@gmail --=20 Mark Rages, Engineer Midwest Telecine LLC markrages@midwesttelecine.com --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .