4 ms·
the top comment trick [ n, 1, n + 1, 0 ][n % 4] can be implemented in J as following : f =: ]`1:`>:`0:@.(4&|)"0 Then: (,. ; #: ; [: #: f) i.16 0 0
by Pompidou 1y ago
the top comment trick [ n, 1, n + 1, 0 ][n % 4] can be implemented in J as following :
f =: ]`1:`>:`0:@.(4&|)"0
Then:
(,. ; #: ; [: #: f) i.16
0 0 0 0 0 0 0 0 0
1 0 0 0 1 0 0 0 1
2 0 0 1 0 0 0 1 1
3 0 0 1 1 0 0 0 0
4 0 1 0 0 0 1 0 0
5 0 1 0 1 0 0 0 1
6 0 1 1 0 0 1 1 1
7 0 1 1 1 0 0 0 0
8 1 0 0 0 1 0 0 0
9 1 0 0 1 0 0 0 1
....
- betasilly 1y agoHello fellow J programmer. In statistic you can estimate the population size by coloring fishes that you put in a lake and some time later you fish in that lake, the proportion of colored fishes allow you to estimate the size of the population. Four month ago I posted some J identities [1] and you were the only one which commented, that means that in this capture I only got one fish and it was the colored fish. This imply that there must be very few J programmers HN, or more precisely, very few of them that post J related material. The parent's comment (also mine) has a style that was designed not to scare non J programmers. One should also consider that some people dislike J code so downvotes are the usual result except when the post provides some additional insight. Finally, thank you for this small J lesson, is a pleasure to find here fellow J programmers. [1] https://news.ycombinator.com/item?id=42859077 https://news.ycombinator.com/item?id=42859077