The question is, do you get a unique key (signature) if you rotate a row so that the first occurrence of the minimum value is first? I thought the answer was yes after thinking about it for a minute. I could be wrong.
On Sat, May 16, 2020 at 5:53 PM Raul Miller <rauldmil...@gmail.com> wrote: > A critical question here is whether the minimum value can appear more > than once in each row, or whether the examples (where each value is > has a unique appearance in each row) are adequately complex. > > Thanks, > > -- > Raul > > On Sat, May 16, 2020 at 8:15 PM Roger Hui <rogerhui.can...@gmail.com> > wrote: > > > > 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 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
