Thanks Bob that was very helpful as I was guilty of the mnemonic sin!
Sent from my iPhone > On Apr 17, 2017, at 5:20 PM, 'Pascal Jasmin' via Programming > <[email protected]> wrote: > > You can copy beta to a new directory and run each independently. > > > > > > ________________________________ > From: Michael Goodrich <[email protected]> > To: [email protected] > Sent: Monday, April 17, 2017 5:14 PM > Subject: Re: [Jprogramming] J weirdness #2 - A nasty surprise > > > > This is getting interesting; I was already impressed with Js speed being only > twice as slow as the C version, and faster than the R version of the same > code. > > Looking forward to that 806 beta 3! > > Btw I should uninstall the latest (stable) and start afresh? > > > Sent from my iPhone > >> On Apr 17, 2017, at 5:03 PM, Raul Miller <[email protected]> wrote: >> >> I think you were surprised by >> http://www.jsoftware.com/help/dictionary/special.htm >> >> Specifically the special handling for +/ .* (which is handled at >> parsing time rather than at execution time - the way you have things >> arranged, the parser will not see +/ .* and hypothetically you could >> arrange for sum .* in contexts where sum was defined differently). >> >> I hope this helps, >> >> -- >> Raul >> >> >> On Mon, Apr 17, 2017 at 4:51 PM, Michael Goodrich >> <[email protected]> wrote: >>> Greetings: >>> >>> Got a nasty surprise today. have a non-trivial J app with the following >>> supporting original definitions: >>> >>> sum =. +/ >>> dot =. +/ . * >>> sqrd =. *: >>> ssq =. +/ @: sqrd >>> >>> >>> Which I changed (thinking I was being elegant) to >>> >>> sum =. +/ >>> dot =. sum . * >>> sqrd =. *: >>> ssq =. sum @: sqrd >>> >>> After this change the run time increased by a factor of 5! >>> >>> Insights? >>> ---------------------------------------------------------------------- >>> 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
