So why not change the documentation to call _. NaN instead of indeterminate? Cuts down on the confusion since it is not indeterminate.
On Sun, Feb 24, 2008 at 10:40 AM, Henry Rich <[EMAIL PROTECTED]> wrote: > I think you are replying to a different argument than the > one I was trying to make. > > I wasn't suggesting that _. be 'above that' in the sense of > following certain J-defined rules independent of the > IEEE spec. That would be OK but if it's too hard, > let it go. > > I am happy with all the implementation decisions you have made. > I am particularly happy with raising error when _. would > be created. > > My only objection is to using the name 'NaN'. Maybe you use > a NaN for _., but I see no reason to pollute the documentation > with that term. I AM suggesting that the language spec be > 'above that', because NaN is a new and unnecessary concept > within J numbers. > > And _. IS a number. qbeta tells me so: > > 9!:14'' > j602/beta/2008-02-22/22:30 > 3!:0 (_.) > 8 > > Don't change a line of code. Do change the doc of 128!:5 to say > it checks for the presence of _. rather than of NaN. Do change > 'NaN error' to either 'domain error' (preferred) or '_. error' . > > The only appearance of NaN in the docs should be the one in _., > which is > > The indeterminate _. is provided to aid in dealing with > NaN (not a number) in data from external sources... > > This makes clear that NaN is IEEE, not J. Occam's razor. > > Henry Rich > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Eric Iverson > > Sent: Sunday, February 24, 2008 12:08 PM > > To: Beta forum > > Subject: Re: [Jbeta] Use of the name 'NaN' deprecated > > > > Your saying _. is indeterminate and has nothing to do with > > the IEEE spec of > > Nan doesn't make it so. Our conclusions are that trying to > > make J 'above > > that' is a fools game that has a very high performance cost > > for all fp > > operations. The hard, unavoidable fact is that J uses the > > IEEE fp spec as > > provided by the hardware and compiler. To do otherwise is not > > worth the > > effort and has far too high a cost. > > > > If you are interested and concerned about _. (whatever it is > > called), I > > strongly suggest you take a look at what is in the current > > beta as that is > > what is going to be in the release. > > > > ----- Original Message ----- > > From: "Henry Rich" <[EMAIL PROTECTED]> > > To: "'Beta forum'" <[email protected]> > > Sent: Sunday, February 24, 2008 11:47 AM > > Subject: [Jbeta] Use of the name 'NaN' deprecated > > > > > > > Roger and Eric have referred to NaN in their messages. I suggest > > > that this usage should be avoided. > > > > > > NaN is meaningful only in reference to the IEEE floating-point > > > spec. > > > > > > J is above that. J deals with numbers. Floating-point is an > > > implementation detail that should not be alluded to in the > > > description of the language. > > > > > > _. is indeterminate. It is not NaN. For one thing, it is > > > a number (at least it used to be - I haven't had the courage > > > to move to rbeta yet), while NaN is explicitly not a number. > > > And, there are many values and kinds of NaN, but only one > > > indeterminate. > > > > > > So, NaNs in external sources produce unpredictable results. > > > Use of _. produces unpredictable results. But they are > > > not the same things. > > > > > > Henry Rich > > > > > >> -----Original Message----- > > >> From: [EMAIL PROTECTED] > > >> [mailto:[EMAIL PROTECTED] On Behalf Of Eric Iverson > > >> Sent: Sunday, February 24, 2008 9:37 AM > > >> To: Beta forum > > >> Subject: Re: [Jbeta] issues not yet resolved > > >> > > >> I am sorry to say that we won't get fixes for these two > > >> problems into this > > >> release. We have just run out of time and need to get this > > >> release out so we > > >> can clear the decks for the next round of activities. The NaN > > >> problem turned > > >> into a surprisingly difficult mess and took much longer > > than expected. > > >> > > >> Your two bugs will be at the top of the list for 602. > > >> > > >> ----- Original Message ----- > > >> From: "bill lam" <[EMAIL PROTECTED]> > > >> To: "Beta forum" <[email protected]> > > >> Sent: Saturday, February 02, 2008 12:05 AM > > >> Subject: [Jbeta] issues not yet resolved > > >> > > >> > > >> > [Jbeta] for-loop, continue, switch-case 30 Sep 2007 > > >> > > > http://www.jsoftware.com/pipermail/beta/2007-September/002383.html > > >> > > > >> > [Jbeta] m&i. and boxed unicode 30 Sep 2007 > > >> > > > http://www.jsoftware.com/pipermail/beta/2007-September/002382.html > > >> > > > >> > Will they be fixed? > > >> > > > >> > > ---------------------------------------------------------------------- > > >> > 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 > > ---------------------------------------------------------------------- > > 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
