This looks like a good addition to my growing set of "array-thinking" examples.
On Thu, Sep 25, 2014 at 12:32 PM, Roger Hui <rogerhui.can...@gmail.com> wrote: > Compared to the other solutions posted so far, I believe it is more > straightforward to do a long sequence of dice rolls and then split it up > according to your specified criteria. The split point are where the > _previous_ roll is _not_ a 6. Thus: > > x=: 1+1e4 ?@$ 6 NB. long sequence of dice rolls > x > 5 4 6 1 5 4 5 6 1 3 5 1 2 3 3 6 5 2 4 5 6 5 5 3 6 2 4 4 1 3 6 4 2 1 5 6 1 6 > 6 6 6 6 5 4 6 1 2 3 2 5 1 2 1 3 2 ... > (}:1,6~:x) <;.1 x > > ┌─┬─┬───┬─┬─┬─┬───┬─┬─┬─┬─┬─┬─┬───┬─┬─┬─┬───┬─┬─┬───┬─┬─┬─┬─┬───┬─┬─┬─┬───┬───────────┬─┬───┬─┬─┬─┬─┬─┬─┬─┬─┬─┬ > │5│4│6 1│5│4│5│6 1│3│5│1│2│3│3│6 5│2│4│5│6 5│5│3│6 2│4│4│1│3│6 4│2│1│5│6 > 1│6 6 6 6 6 5│4│6 1│2│3│2│5│1│2│1│3│2│ ... > > └─┴─┴───┴─┴─┴─┴───┴─┴─┴─┴─┴─┴─┴───┴─┴─┴─┴───┴─┴─┴───┴─┴─┴─┴─┴───┴─┴─┴─┴───┴───────────┴─┴───┴─┴─┴─┴─┴─┴─┴─┴─┴─┴ > > > > > On Thu, Sep 25, 2014 at 6:06 AM, Johann Hibschman <jhibsch...@gmail.com> > wrote: > > > Hi all, > > > > For fun, I've been running some statistics for a game with an unusual > > rule for rolling dice: if a 6 is rolled, roll again and add the > > result, repeating on any subsequent 6s. I wanted to implement this in > > J, collecting all the individual rolls (rather than just the sum.) > > > > It seems like there should be a more clever and elegant way to do > > this, but this is what I have: > > > > NB. Simple roll. > > roll0 =: >:@? > > > > NB. This seems to work, but it's not very clever. > > roll =: 3 : 0 > > r =. >:?y > > if. r=y do. r=. r,(roll y) end. > > r > > ) > > > > NB. Attempt at iterating via power. Fails because repeats > > NB. signal termination. > > roll0^:(6&=)^:(<_) 6 > > > > NB. Attempt at iterating via agenda. Not even close yet. > > NB. ]`(]+$:) @. (=&6) NB. where to stick in the roll? > > > > This gives what I expect: > > > > roll"0 ] 10#6 > > 6 1 0 > > 3 0 0 > > 3 0 0 > > 2 0 0 > > 5 0 0 > > 2 0 0 > > 6 6 2 > > 2 0 0 > > 1 0 0 > > 6 3 0 > > > > But is there a better way to do this? Also, are there any known issues > > with the RNG? I've not gathered enough statistics to prove it, but the > > results look clumpier (more identical values in a row) than I expect. > > Now, I know that's a common cognitive bias, so it may just be me, but > > is there a discussion of the quality of the RNG somewhere? > > > > Thanks, > > Johann > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
