You might want to try f{iota}f on a vector rather than
a two-dimensional array.Tolerant i. on a float array used to be very slow (compared to i. on lists) in J, but apparently Roger has been improving things. Formerly you needed to use i.!.0 to get good performance, but your numbers show that to be no longer true. Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: Friday, June 01, 2007 2:15 PM > To: General forum > Subject: Re: [Jgeneral] Re: Challenge to expert J'ers > > RH> I suggest you try the benchmarks in > RH> http://www.jsoftware.com/jwiki/Essays/Index_in_Nub > RH> in APL. > > I just did ( a simplified version) and there is definitively a major > problem with the dyadic iota of Dyalog APL. > These results points to either a "bug" in both interpreters or a > mystery... > It seems to me that APL implementers of Dyalog would be best > to require > your services for dyadic iota for float... > Here are the results (all tests done on my PC, Dell OptiPlex GX270, > Processor x86 Family 15 Model 2 Stepping 9 GenuineIntel > ~2593 Mhz > > i=:2e5$1e5?2e9 > f=:i%i+0.1 > J J 6.01 APL Dyalog 10.0.2 > Integer .i~i 0.065 i{iota}i 0.109 > Float .i~f 2.826 f{iota}f 1402.875 > > Can anyone confirm these results and add other APL > implementations if they > so have ? > Roger ! How can we explain that huge difference between .i~f > and f{iota}f > ? > > > > Paul Gauthier > APL Software Developer - Senior > [EMAIL PROTECTED] > Phone: 312-739-3467 > Fax: 312-739-3496 > > CheckFree. The Company that Powers Payment on the WebSM. > http://www.checkfree.com/paybillsonline > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
