Basically the ( , ) is getting around the issue that Raul has nicely described - we want to turn the shape of the boxes into a simple list
u&v applies the verb v to x and y before running x u y i.e. x u&v y <==> (v x) u (v y) where u =: +/ .*&.>/ and v =: , The last ( / ) is the dyadic form - Table [1] and applies each cell of x to the whole of y An alternative formulation that does the same thing is: (,tA) +/ .*&.>"0 _ (,tB) [1] http://www.jsoftware.com/docs/help701/dictionary/d420.htm On Tue, Nov 8, 2011 at 11:17 AM, Jan Jacobs <[email protected]> wrote: > Wow, that is exactly what I wanted, it is "equivalent" with +/ . * > applied the unpartitioned matrices A and B. > Can you explain why you've added /&, ? > Thanks for the help! > > On Mon, Nov 7, 2011 at 9:50 PM, Ric Sherlock <[email protected]> wrote: >> or did you want >> tA +/ .*&.>/&, tB >> ┌─────────┬─────────┬─────────┐ >> │330 345 │360 375 │ 390 405│ >> │870 921 │972 1023 │1074 1125│ >> ├─────────┼─────────┼─────────┤ >> │1410 1497│1584 1671│1758 1845│ >> │1950 2073│2196 2319│2442 2565│ >> ├─────────┼─────────┼─────────┤ >> │2490 2649│2808 2967│3126 3285│ >> │3030 3225│3420 3615│3810 4005│ >> └─────────┴─────────┴─────────┘ >> >> >> On Tue, Nov 8, 2011 at 9:40 AM, Ric Sherlock <[email protected]> wrote: >>> (,tA) +/ .*&.> (,tB) >>> >>> On Tue, Nov 8, 2011 at 9:09 AM, Jan Jacobs <[email protected]> wrote: >>>> ls, >>>> for educational purposes I want to breakdown a CUDA matrix >>>> multiplication in smaller parts. >>>> What I do not understand is that for B=:A =: i.6 6 >>>> tA =: (2 2,:2 2)<;._3 A >>>> tB =: (2 2,:2 2)<;._3 B >>>> tA (+/ . *)&.> tB >>>> works fine, but >>>> tA =: (2 6,:2 6)<;._3 A >>>> tB =: (6 2,:6 2)<;._3 B >>>> tA (+/ . *)&.> tB >>>> does not: >>>> |length error >>>> | tA (+/ .*)"1&.>tB >>>> >>>> The shapes of the various boxes are as expected. >>>> What is going wrong? >>>> Thanks in advance for the help. >>>> Jan. >>>> >>>> >>>> -- >>>> Jan Jacobs >>>> Esdoornstraat 33 >>>> 5995AN Kessel >>>> W: www.sommaps.com >>>> T: +31 77 462 1887 >>>> M: +31 6 23 82 55 21 >>>> E: [email protected] >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>> >>> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > > > -- > Jan Jacobs > Esdoornstraat 33 > 5995AN Kessel > W: www.sommaps.com > T: +31 77 462 1887 > M: +31 6 23 82 55 21 > E: [email protected] > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
