Hi, thanks! But as Raul pointed out, this does not allow me to specify max iterations.
Regards, Anton Wallgren On 26 May 2020, 08:39 +0200, 'Rob Hodgkinson' via Programming <[email protected]>, wrote: > Hi Anton, welcome to J. > > This is a further parameter to the power operator (^:) described here: > > https://code.jsoftware.com/wiki/Vocabulary/Loopless > <https://code.jsoftware.com/wiki/Vocabulary/Loopless> Section “Types of > Loops” and the row in the table “Apply a verb repeatedly”, “Until a condition > is met”. > Use Power ([x] u^:v^:_ y) > > For your example, double while a condition (eg let’s say while the sequence > is < 100 and stop with the value that breaches that condition …) > > 2&* ^:(100>])^:_ (1) NB. Sequence here is 1,2,4,8,16,32,64,128 > 128 > > 2&* ^:(100>])^:_ (5) NB. Sequence is 5, 10, 20, 40, 80, 160 > 160 > > Best, Rob > > > On 26 May 2020, at 4:09 pm, Anton Wallgren <[email protected]> wrote: > > > > Hello! > > > > Fairly recent J enthusiast here. I’m wondering about the idiomatic way to > > iterate at most n times? I.e. do f^:n y, but with the possibility of an > > early exit if some condition is met. Is it (u F. ]) y, where u is f but > > with some Z:’s added? E.g > > > > f=: 2&* > > MAX=: n > > > > u=: monad define > > _2 Z: -.*MAX=: MAX - 1 > > _2 Z: some other condition > > f y > > ) > > > > But then you need to globally assign and reassign MAX and this doesn’t feel > > very elegant. Another option of course is to use a for-loop with break. > > > > Thanks, Anton Wallgren > > ---------------------------------------------------------------------- > > 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
