My late night laziness and I got bitten by the 13 : definition doesn’t always work correctly with both x and y variables. Which I just assumed was working correctly.
Now when I fix the definition of matmul3 so it works correctly (as Elijah pointed out) the variable representation does not incur a worrisome time penalty: (1+i. 4 3) ([: +/ *)"1 _ (1+i. 3 4) 38 44 50 56 83 98 113 128 128 152 176 200 173 206 239 272 matmul3 =: ([: +/ *)"1 _ (1+i. 4 3) matmul3 (1+i. 3 4) 38 44 50 56 83 98 113 128 128 152 176 200 173 206 239 272 10 timex 'bmat1 ([: +/ *)"1 _ bmat2’ 0.0464441 10 timex 'bmat1 matmul3 bmat2’ 0.0471224 (bmat1 matmul3 bmat2) -: bmat1 ([: +/ *)"1 _ bmat2 1 Thanks for showing me the error > On Jul 19, 2022, at 5:15 AM, Elijah Stone <elro...@elronnd.net> wrote: > > You are measuring two completely different things. > > 10 timex'bmat1 ([: +/ *)"1 _ bmat2' > 0.0482293 > 10 timex'bmat1 ([: +/ *"1 _) bmat2' > 0.115583 > (bmat1 ([: +/ *)"1 _ bmat2) -: (bmat1 ([: +/ *"1 _) bmat2) > 0 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
