The change is much more than substituting NaN for _. or vice versa. You should read the page for _. in the J6.02 qbeta.
Absolutely no plans to change 0%0 giving 0. ----- Original Message ----- From: [EMAIL PROTECTED] Date: Monday, February 25, 2008 16:25 Subject: Re: [Jbeta] Use of the name 'NaN' deprecated To: [email protected] > I agree with Henry. > > As the Dictionary reads now (and has always read since the 1991 > version), the only reference to _. is its "Indeterminate" entry > itself, namely: > > Indeterminate _. > The indeterminate _. results from expressions such > as _-_ (infinity > minus infinity) and from expressions (such as 3+_.) > in which an > indeterminate argument occurs. > > A clarification how _. relates to = (and, by induction i. e. ~: >: > <: etc.) is dearly missing in my opinion. (3=_. > ? _.=_. ?) > > If the clarification should be that the results are "entirely > fortuitous" [Roger's words] or "platform-dependent", that is fine > with me, too. I just think the rules need to be spelled out. > (I also think it should also be made explicit that _. propagates only > in "arithmetic expressions" as opposed to, say, > <_. or 2#_. .) > > I've spent enough days on making _/__/_. work on various platforms > and am certainly aware of the close ties to IEEE > arithmetic. However, > just shelling another moniker such as "NaN" for _. in the Dictionary > doesn't help a bit to define how _. is supposed to work. > If anything, > any spurious or explicit reference to NaN or IEEE just raises further > questions just how IEEEish J's arithmetic is supposed to be, without > answering this either. Just stick to the word > "indeterminate", as > Henry suggests. > > Beyond the references to "NaN", I have another quarrel with the > two new foreigns: I am missing a rank specification for these > verbs. > > Martin > > PS: > > (And the only way to deal with _. in J data is to get rid of it!) > > We'd love too, but up to J Rel. 6.01 the Dictionary has been silent > on how to do this. > > PPS: Any plans to kill off "0%0 ==> 0"? ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
