I'll be damned! Rank 1 _ ! Thank you, Raul.
On 12/7/2011 11:10 AM, Raul Miller wrote: > Oh, it's certainly doable -- it's that 'simple J' makes some things more > complicated. > > That said, inner product is not very complicated: > > mv =: ([: +/ *)"1 > mm =: [: |: (mv"2 1 |:) > > $ (i.3 4 5)+/ .*i.5 6 7 > 3 4 6 7 > > ((i. 3 4 5) mm i.5 6 7) -: (i. 3 4 5) +/ .* i.5 6 7 > |length error: mm > > ((i. 3 4 5) ([: +/ *)"(1 _) i.5 6 7) -: (i. 3 4 5) +/ .* i.5 6 7 > 1 > > And, my other example becomes: > ([:< [: toupper>)"0 'this';'is';'a';'test' > > And, in general, artificially restricting vocabulary can make concepts > clearer. For example, it can also be instructive to express inner product > without using J's multiply verb. > > However, "instructive" and "simple" are not the same thing. Also, sticking > with a single restriction for too long enshrines the restriction and leads > attention away from the concepts that should have been learned. > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
