Kaba
Posts:
289
Registered:
5/23/11


Re: Is there a name for this notation?
Posted:
Oct 9, 2011 8:52 AM


A N Niel wrote: > In article <4e919166$0$29981$c3e8da3$5496439d@news.astraweb.com>, > Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote: > > >[...]> > > You'd need either a digit for 100, or some notation for grouping digits. > > E.g.: > > > > 2^10 => A > > 2^11 => B > > 2^12 => C > > ... > > > > but since we can't realistically have an infinite number of unique symbols, > > a grouping notation might be better: > > > > 2^100 + 2^50 + 2^10 + 2^2 = (100)(50)(10)2 > > Since it is just a set anyway, maybe {100,50,10,2}
In the case of "base 2", this can be seen as a sparse form of the traditional base2 representation. Let I subset NN. Then the value of I is given by
V(I) = sum_{i in I} 2^i,
i.e. the set I encodes the positions of the 1bits, rather than giving a "dense" tuple of coefficients where some elements might be 0. Higher bases probably sacrifice some property, possibly uniqueness.
 http://kaba.hilvi.org

