Base representation is also done with #. and #: But the inverse of #. and antibase #: don't work as expected:
0.1 #. 1 2 3 3.21 0.1 #.^:_1] 3.21 0.1 0.1 0.1 #: 3.21 0 0 0.01 0.1 0.1 0.1 #. 0 0 0.01 0.01 _3 #. 1 2 0 2 _7 _3 #.^:_1] _7 _1 _1 _3 _3 _3 _3 #: _7 0 _1 _1 _1 _3 _3 _3 _3 #. 0 _1 _1 _1 _7 --- Arved Sandstrom <[EMAIL PROTECTED]> wrote: > It's probably not as remarkable as it sounds. :-) The most basic operation - > that of doing _3b1202, or suchlike - will happen correctly even if the > implementor only ever thinks of positive bases. > > You may have noted too that using a negative base in J will accommodate a > negative representation, as in _3b_121 = _4, and I do not believe that this > is conventional. If it was accepted it should probably mean > > +/ 9 _3 1 * _1 2 1 = _14 > > anyway. But that is maybe leaving up to the user not to be stupid; for > example in J601 you can do 2b222, and _5b879. > > Arved Sandstrom > > [ SNIP ] > > Then I thought back to a math competition I was once in, where they > > first had a speaker talk about a subject that the competitors > > presumably had never been exposed to before, and then had us take a > > test on the subject. > > > > The subject of the talk was negative bases. For example base negative > > 3, where 120 is equal to > > > > 1*(-3)^2 + 2*(-3)^1 + 0*(-3)^0 = 3 > > > > As an aside, one interesting aspect of negative bases is that you > > never need to negate a number. For example, -7 = 1202. > > > > So having discovered that J seemingly handles arbitrary bases, I > > tried negative bases, and sure enough, it works: > > > > _3b1202 > > _7 > > > > _That_ was a pleasant surprise! > > > > regards, > > > > Geoff > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ____________________________________________________________________________________ Be a better Heartthrob. Get better relationship answers from someone who knows. Yahoo! Answers - Check it out. http://answers.yahoo.com/dir/?link=list&sid=396545433 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
