((n i."_1 <./"1 n)|."_1 n) </. n ┌───────┬───────┐ │2 4 1 3│2 3 4 1│ │3 2 4 1│3 4 1 2│ │1 3 2 4│4 1 2 3│ │4 1 3 2│1 2 3 4│ └───────┴───────┘
Rotate each row so that the minimum item is first, then use those rotated rows as keys. On Sat, May 16, 2020 at 4:44 PM Skip Cave <s...@caveconsulting.com> wrote: > I have run across this issue a few times in the past. > The following 8x4 array has several rows that are 'rotational duplicates'. > > ]n=.8 4$2 4 1 3 2 3 4 1 3 4 1 2 3 2 4 1 1 3 2 4 4 1 2 3 1 2 3 4 4 1 3 2 > > 2 4 1 3 > > 2 3 4 1 > > 3 4 1 2 > > 3 2 4 1 > > 1 3 2 4 > > 4 1 2 3 > > 1 2 3 4 > > 4 1 3 2 > > > Is it possible to develop a verb that would find the rows that are > rotational duplicates of each other. That is, find all the rows that would > be the same, if each row was rotated some integer value in the first > dimension. The output of the verb would be the same shape array, but with > each duplicate row rotated such that they show as identical. Picking the > 'standard' rotation for a set of rotational duplicates is up to the > implementer. > > > Skip > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
