That is ambiguous, in the general case. Practically speaking, however, it's defined by context. If the data is "signed" the most significant bit is a "negative bit". If the data is "unsigned" the most significant bit is a "binary digit".
That said, some operations are useful regardless of this distinction (which was the motivation for using this representation). For example, if you have implemented addition, you can use the same addition implementation for both "signed" and "unsigned" data. The mechanics are the same, only the symbolism differs. -- Raul On Thu, Dec 29, 2011 at 11:00 PM, Linda Alvord <lindaalv...@verizon.net> wrote: > How can you tell when the leading digit is a "negative bit" or a "binary > digit"? > > In the situation above the same number can represent two different binary > numbers. If 1 1 0 1 is sometimes 13 or might be _5 when is each > appropriate?v. Isn't that the source of some problems? > > The spaces indicate that the number is probably a single binary number, but > it could be a list of true and false indicators. You would need to know the > context to determine the difference. > > Linda > > -----Original Message----- > From: programming-boun...@jsoftware.com > [mailto:programming-boun...@jsoftware.com] On Behalf Of Kip Murray > Sent: Thursday, December 29, 2011 8:25 PM > To: Programming forum > Subject: Re: [Jprogramming] How #: should have been designed > > > tcrRaul }: i:4 > 1 0 0 > 1 0 1 > 1 1 0 > 1 1 1 > 0 0 0 > 0 0 1 > 0 1 0 > 0 1 1 > > tcrRandy }: i:4 > 1 1 0 0 > 1 1 0 1 > 1 1 1 0 > 1 1 1 1 > 0 0 0 0 > 0 0 0 1 > 0 0 1 0 > 0 0 1 1 > > tcrRaul > {.@#:@(,: (2 * >./@,)) > > tcrRandy > (0 > ]) ,"0 1 #: > > > On 12/29/2011 8:41 AM, Randy MacDonald wrote: >> On 12/8/2011 4:39 PM, Raul Miller wrote: >>> {.@#:@(,: 2 *>./@,)i:2 >> ((0>]),"0 1#:) i:2 NB. seems to work just as well, and more obviously >> handles the sign bit. >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
