On Fri, Feb 15, 2013 at 11:29 AM, Dan Drake <ddr...@pugetsound.edu> wrote: > This seems weird to me: > > sage: (-10).bits() > [0, -1, 0, -1] > > It makes it look like binary now includes -1 along with 0 and 1, making > it..ternary?
I can't think of a better (finite) definition that matches what is expected for 10.bits(). > I guess that the bits() function is supposed to satisfy > > x == sum(b*2^e for e, b in enumerate(x.bits())) > > ...but you have to interpret b as a regular integer -- and not a bit -- > for that to be true, since -1 equals 1 in the integers mod 2. And > indeed, the parent of all the "bits" is the Integer Ring and not GF(2) > or Integers(2). > > At the very least, I think this deserves a note in the bits() > documentation. +1 > Or, what might be less popular, a change to bits() to > somehow return a sign -- maybe a tuple (sign, [list of bits])? This would be quite backwards incompatible, even an error would be more reasonable. - Robert -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
