Hmm, you just want the keys: rotate each row so that the minimum item is first.
(n i."_1 <./"1 n)|."_1 n 1 3 2 4 1 2 3 4 1 2 3 4 1 3 2 4 1 3 2 4 1 2 3 4 1 2 3 4 1 3 2 4 On Sat, May 16, 2020 at 5:11 PM Roger Hui <rogerhui.can...@gmail.com> wrote: > ((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
