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
