On Tue, Mar 2, 2010 at 5:22 PM, Dan Bron <[email protected]> wrote: > Raul wrote: >> We can use /. for convolution (+//.@(*/)) of one dimensional >> arrays, but do we have anything that simple for higher >> dimensional arrays? > > I haven't looked into it, but would RE Boss' proposal for a different > definition of /. (oblique) help generalize +//.@(*/) ? > > http://www.jsoftware.com/pipermail/programming/2006-December/004410.html
It might, but I do not see how. Using the above definition of obl and the 2d data from that wiki page: h=:".;._2]0 :0 _8 1 _7 _2 _9 4 4 5 _5 2 7 _1 _6 _3 _3 _6 9 5 ) f=:".;._2]0 :0 _5 2 _2 _6 _7 9 7 _6 5 _7 1 _1 9 2 _7 5 9 _9 2 _5 _8 5 _2 8 5 ) g=:".;._2]0 :0 40 _21 53 42 105 1 87 60 39 _28 _92 _64 19 _167 _71 _47 128 _109 40 _21 58 85 _93 37 101 _14 5 37 _76 _56 _90 _135 60 _125 68 53 223 4 _36 _48 78 16 7 _199 156 _162 29 28 _103 _10 _62 _89 69 _61 66 193 _61 71 _8 _30 48 _6 21 _9 _150 _22 _56 32 85 25 ) g -: f +/obl@(*/) h 0 $ f +/obl@(*/) h 16 Thanks, -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
