The performance bug has now been fixed for the next release. y=: 1e6 [EMAIL PROTECTED] 2 ts=: 6!:2 , 7!:[EMAIL PROTECTED] ts '(}.+.}:) y' 0.00510168 3.14662e6 ts '2+./\y' 0.00363596 2.09843e6 ts '3+./\y' 0.00973976 1.04966e6 ts '4+./\y' 0.0114389 1.04966e6 ts '5+./\y' 0.0122412 1.04966e6 ts '50+./\y' 0.0124204 1.04973e6
----- Original Message ----- From: Roger Hui <[EMAIL PROTECTED]> Date: Friday, March 14, 2008 13:55 Subject: Re: [Jprogramming] expanding timed data into time-series To: Programming forum <[email protected]> > There is a performance bug somewhere in 2 +./\y . > > y=: 1e6 [EMAIL PROTECTED] 2 > > ts '2 +./\y' > 0.124445 2.09856e6 > > ts '3 +./\y' > 0.024378 1.04966e6 > ts '4 +./\y' > 0.024892 1.04966e6 > ts '5 +./\y' > 0.0258469 1.04966e6 > > > > ----- Original Message ----- > From: Dan Bron <[EMAIL PROTECTED]> > Date: Friday, March 14, 2008 11:00 > Subject: Re: [Jprogramming] expanding timed data into time-series > To: Programming forum <[email protected]> > > > Arie: > > > I do not get your result? > > > > Put this down to "the vaguaries of benchmarking". The > > difference is not significant in either case. > > > > OTOH, I just did different test: > > > > ts > > =: 6!:2 , 7!:2@:] > > Y =: ?.@:$&2]1e7 > > > > > > ts&>'(}. +. }:) Y';'2 +./\ Y' > > 0.0517359 5.03327e7 > > 0.227543 > 3.35559e7> > > > > 0.01 round (%"1<./) ts&>'(}. +. }:) Y';'2 +./\ Y' [ load'misc' > > 1 1.5 > > 4.69 1 > > > > This difference *is* significant, and it corroborates Oleg's > > assertion: > > > I thought it was shown that old style shift > > > is more efficient than infix. > > > > which surprises me, given the links I cited > > before. Roger, can you clarify or > > elaborate? > > > > Oleg, I haven't been watching the Forums closely lately; would > > you point me to the messages that highlighted this behavior > > (i.e. shift+operate is faster than infix)? > > > > -Dan > > > > PS: This latter benchmark is not relevant to the problem > > at hand, because of the requirement for catentation I > indicated > > earlier. Neither method is a clear winner in that case > > (i.e. their performance is comparable). ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
