The documentation does refer mostly to _. and only mentions NaN once or twice. Mention of NaN is unavoidable, even desirable, as the only legitimate use of _. is to deal with NaN in data from external source. (And the only way to deal with _. in J data is to get rid of it!)
----- Original Message ----- From: Henry Rich <[EMAIL PROTECTED]> Date: Sunday, February 24, 2008 8:47 Subject: [Jbeta] Use of the name 'NaN' deprecated To: 'Beta forum' <[email protected]> > 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 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
