So "8" would have to be represented by "0 1 0 0 0".
On Wed, Dec 14, 2011 at 12:11 PM, Raul Miller <rauldmil...@gmail.com> wrote:
> For two's complement to work, you need the leading bit to be 0 for
> non-negative numbers.
>
> Limiting the range of considered numbers (as you would for a fixed
> width bit sequence) is one tool you can use here.
>
> This can also be looked at as a padding issue (and the rude treatment
> #:'s results get from frame fill can be motivating, for treating this
> issue properly).
>
> --
> Raul
>
> On Wed, Dec 14, 2011 at 11:02 AM, Devon McCormick <devon...@gmail.com>
> wrote:
> > The "embarassing" example happens because the full scope of "two's
> > complement" notation implies fixed-width binary numbers, not the
> > variable-width version given in this thread.
> >
> > On Wed, Dec 14, 2011 at 10:41 AM, Kip Murray <k...@math.uh.edu> wrote:
> >
> >> On 12/14/2011 6:07 AM, Linda Alvord wrote:
> >> > I really don't think that you can ever write a program good enough
> that
> >> the
> >> > the number 8 in binary is _8 in decimals
> >> >
> >> > hcinv 1 0 0 0
> >> > _8
> >>
> >> THAT /IS/ EMBARRASSING !
> >>
> >> > I have lived my mathematical life without being able to write negative
> >> > binary numbers. I have always ignored two's complements as beyond my
> >> scope
> >> > of interest. It is like saying there are no negative numbers. It
> will
> >> be
> >> > ok if 13 stands for _13 and we'll all be happy.
> >> >
> >> > I'm sure that much of the world deals well without imaginary numbers.
> >> > However, they must have been a mess to develop so they work
> flawlessly.
> >> > Note that they do have a strange appearance but if you understand them
> >> you
> >> > get used to them.
> >> >
> >> > In my world, if I want _8 I write _1 0 0 0 which is in the 8
> 4 2
> >> 1
> >> > 8's digit. So what is _14 ?
> >> >
> >> > Linda
> >>
> >> IN YOUR WORLD _14 IS
> >>
> >> - 1 1 1 0
> >> _1 _1 _1 0
> >>
> >> AND IN TWO'S-COMPLEMENT IT IS
> >>
> >> tcng 0 1 1 1 0
> >> 1 0 0 1 0
> >>
> >> ------------------
> >>
> >> stack =: ,.&.|: NB. stack x over y
> >>
> >> hv =: (0 {:: <"1) :: ] NB. return head vector
> >>
> >> Tbln =: 2 2 2 $ 0 0,1 1,1 1,0 1 NB. table for tcng, see opn
> >>
> >> ban =: 0 ,~ 0 ,.~ 0 ,.~ ] NB. build argument, see tcng
> >>
> >> opn =: ] stack~ (0 { [) , Tbln {~ [: < (0 { [) ,~ 2 { [: hv ]
> >>
> >> tcng =: (1 {"1 [: }: [: opn/ ban)"1 NB. TWO'S-COMPLEMENT NEGATIVE
> >>
> >> ----------------------------------------------------------------------
> >> For information about J forums see http://www.jsoftware.com/forums.htm
> >>
> >
> >
> >
> > --
> > Devon McCormick, CFA
> > ^me^ at acm.
> > org is my
> > preferred e-mail
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
--
Devon McCormick, CFA
^me^ at acm.
org is my
preferred e-mail
----------------------------------------------------------------------
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