Looking at the J implementation, it's pretty clear that jsignal(EVNAN); R 0; would signal the NaN error.
But J has a macro -- NANTEST -- which I don't adequately understand, and a variation of this logic is used in the NAN1 macro. (I was looking at the implementation to try and figure out what kind of work is involved here... it looks like there's a number of routines in va2.c and presumably va2ss.c which would need this test. But finding the right place for the test would require understanding what the test was testing...) -- Raul On Fri, May 6, 2022 at 2:20 PM Raul Miller <rauldmil...@gmail.com> wrote: > > Yes: > > _. in an argument here should signal a NaN error. > > Thanks, > > -- > Raul > > On Fri, May 6, 2022 at 7:15 AM Elijah Stone <elro...@elronnd.net> wrote: > > > > _. may give garbage results. It shouldn't hang. > > > > On Fri, 6 May 2022, Razetime wrote: > > > > > Although this does not seem like intended behaviour, it is worth > > > mentioning > > > that NuVoc <https://code.jsoftware.com/wiki/Vocabulary/underdot> > > > explicitly > > > states that _. is not recommended for use in J computations. > > > > > > On Fri, May 6, 2022 at 4:30 PM <jph.but...@mailoo.org> wrote: > > > > > >> Hello, > > >> > > >> > > >> > > >> _. does not mix well with logical operators. The following hang and use a > > >> lot of CPU on J 9.03 (Windows and Linux): > > >> > > >> > > >> > > >> 1 +. _. > > >> > > >> 1 *. _. > > >> > > >> +. / 8 0 _. > > >> > > >> > > >> > > >> Note, that I have no particular use for these sentences, I just stumbled > > >> across them due to a bug in my program. > > >> > > >> > > >> > > >> Philip > > >> > > >> > > >> > > >> > > >> ---------------------------------------------------------------------- > > >> 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
