Thank you, didn't know about interval index. Sun, 8 May 2016 19:27:32 +0800 bill lam <[email protected]>: > It is called interval index (dyad I.), please see help > documentation for detail. > > 2.5 5 7.5 I. 1 3 3 3 4 7 7 8 8 9 > 0 1 1 1 1 2 2 3 3 3 > #/.~ 2.5 5 7.5 I. 1 3 3 3 4 7 7 8 8 9 > 1 4 2 3 > > > Вс, 08 май 2016, dahn oak написал(а): > > Hello, I want to mimic this Mathematica code: > > > > BinCounts[x, {div}] > > > > It returns an array where i-th element is a count of elements in x that > > belongs to interval [div_i, div_i+1). > > I've succeeded, but want to know if my soulution is adequate enough in > > terms of J programming style. Here it is: > > > > (/:~ x) ((</ }.) +/@:*. (>:/ }:)) div > > > > Example: > > > > ] x =: /:~ ? 10 # 10 > > 1 3 3 3 4 7 7 8 8 9 > > x ((</ }.) +/@:*. (>:/ }:)) 0 2.5 5 7.5 _ > > 1 4 2 3 > > > > It's a histogram > > 1 = # 1 NB. (>:&0 *. <&2.5) > > 4 = # 3 3 3 4 NB. (>:&2.5 *. <&5 ) > > 2 = # 7 7 NB. (>:&5 *. <&7.5) > > 3 = # 8 8 9 NB. (>:&7.5 *. <&_ ) > > > > The main concern is that the }. and {: makes array copies, as far as I > > know. Can I do better, more J-ish solution? > > > > ── > > dahn oak <[email protected]> > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > -- > regards, > ==================================================== > GPG key 1024D/4434BAB3 2008-08-24 > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm
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