So the space saving is actually x5 times 2.09722e7 % 4.19501e6 <<< 4.99932
And space does not depend on argument being power of 2. The idea is to extend this over to y <[EMAIL PROTECTED] 0.3 and for z=. %1+y z <[EMAIL PROTECTED] 256 Does it make sense? For example, the results in j602 between ts 'y <[EMAIL PROTECTED] %0.3' ts 'y <[EMAIL PROTECTED] 0.3' --- Roger Hui <[EMAIL PROTECTED]> wrote: > Integer <[EMAIL PROTECTED] has already been made faster and leaner > in J6.02x as previously discussed in the forum. > The improvement is the greatest when the divisor > is a power of 2. > > y=: 1e6 [EMAIL PROTECTED] 1000 > ts=: 6!:2 , 7!:[EMAIL PROTECTED] > > NB. J6.02x > ts '<.y%3' > 0.215045 2.09721e7 <<< > ts 'y <[EMAIL PROTECTED]' > 0.023161 4.19501e6 <<< > ts 'y <[EMAIL PROTECTED] 256' > 0.0102885 4.19507e6 > > NB. J6.01 > ts '<.y%3' > 0.215612 2.09721e7 > ts 'y <[EMAIL PROTECTED] 3' > 0.216431 2.09722e7 <<< > ts 'y <[EMAIL PROTECTED] 256' > 0.219403 2.09723e7 > > > > ----- Original Message ----- > From: Oleg Kobchenko <[EMAIL PROTECTED]> > Date: Monday, February 12, 2007 6:36 pm > Subject: Re: [Jgeneral] large space overhead > > > How about this > > > > > y=: 1e6 [EMAIL PROTECTED] 1000 > > > > s=: y%3 > > ts '<.s' > > 0.190772 1.25836e7 > > ts '<.y%3' > > 0.209075 2.09721e7 > > ts 'y<[EMAIL PROTECTED]' > > 0.209349 2.09722e7 > > > > ts 'y<[EMAIL PROTECTED]"0]3' > > 0.846868 4.19571e6 > > ts '0.3<[EMAIL PROTECTED]"0 y' > > 0.84268 4.1959e6 > > > > 0.846868 4.19571e6 % 0.190772 1.25836e7 > > 4.43916 0.333427 > > 0.846868 4.19571e6 %~ 0.190772 1.25836e7 > > 0.225268 2.99916 > > > > I.e. if integerization is done memberwise, > > the space savings is three times. > > But at the expense of speed, which should be > > compensated by special code. > > > > > > --- Roger Hui <[EMAIL PROTECTED]> wrote: > > > > > A quick benchmark: > > > > > > x=: 1e6 [EMAIL PROTECTED] 0 > > > y=: 1e6 [EMAIL PROTECTED] 1000 > > > t=: x*y > > > > > > ts=: 6!:2 , 7!:[EMAIL PROTECTED] > > > ts '<.t' > > > 0.201745 1.25836e7 > > > ts '<.x*y' > > > 0.242125 2.09721e7 > > > > > > 0.242125 2.09721e7 % 0.201745 1.25836e7 > > > 1.20015 1.66662 > > > > > > Factor of 1.2 in time and 1.7 in space. Not worth it. > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ____________________________________________________________________________________ Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
