I was about to send something when we had to go out for a bit... My best so far is ((] #~ 1 = I.)~ (0 _1 + ])) ~ assuming I've copied it correctly...
Mike Please reply to mike_liz....@tiscali.co.uk. Sent from my iPad > On 24 Sep 2017, at 18:45, Skip Cave <s...@caveconsulting.com> wrote: > > Marshall, > > Wow! that is neat! I hadn't really understood dyadic I. but this forced me > to try to understand it: > > 8 100 (]#~1=I.) 2 10 45 300 > > 10 45 > > 8 100 I. 2 10 45 300 > > 0 1 1 2 > > 1 = 8 100 I. 2 10 45 300 > > 0 1 1 0 > > (1 = 8 100 I. 2 10 45 300) # 2 10 45 300 > > 10 45 > > 8 100 I. 2 10 45 300 > > 0 1 1 2 > > 1 8 100 I. 2 10 45 300 > > 1 2 2 3 > > 1 8 100 I. 2 10 45 300 450 > > 1 2 2 3 3 > > 1 8 100 350 I. 2 10 45 300 450 > > 1 2 2 3 4 > > 1 8 100 350 I. 300 2 45 10 450 > > 3 1 2 2 4 > > So now I'm getting a feel for I. Reading the terse Vocabulary description > of dyadic I. didn't help much in making the I. functionality clear, at > least for me. The NuVoc description wasn't much more helpful, but the > examples after the description in Nuvoc cleared things up considerably. > > Also, the dissect tool was very helpful in figuring out how J parsed the > whole dyadic verb. Who is the author of the dissect tool? That's a great > help in learning J. > > Skip > > Skip Cave > Cave Consulting LLC > > On Sun, Sep 24, 2017 at 3:14 AM, Marshall Lochbaum <mwlochb...@gmail.com> > wrote: > >> Try >> >> rng =: ] #~ 1=I. >> >> it's about half as fast because I. is not very well-optimized. >> >> Marshall >> >>> On Sun, Sep 24, 2017 at 02:29:31AM -0500, Skip Cave wrote: >>> Here's a function I came up with to select numbers in a vector which are >>> within some range. >>> >>> Find all the numbers between 10 & 100 in a set of random numbers from 0 >> to >>> 200: >>> >>> >>> rng =. 4 : '((({.x)</y)*.(({:x)>/y))#y' >>> >>> >>> 10 100 rng ?50$200 >>> >>> 89 91 32 85 84 27 31 20 28 66 96 93 22 85 39 97 82 35 90 67 34 35 67 95 >> 50 >>> >>> >>> Between 120 & 180: >>> >>> >>> 120 180 rng ?50$200 >>> >>> 148 163 133 165 150 178 121 146 161 179 >>> >>> >>> Is there a more concise/efficient way to select numbers in a range? >>> >>> Skip Cave >>> Cave Consulting LLC >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm