3 ms·
What is group?
by nextaccountic 4y ago
What is group?
- geoah 4y agoSome context would be really nice indeed.
- Jtsummers 4y agohttps://gist.github.com/chrispsn/3450fe6172a7cc441d0819379ed3a32a#a-history-of-group https://gist.github.com/chrispsn/3450fe6172a7cc441d0819379ed... <- Here you go, some context about what group is and does (or was and did, in this case) in the K language.
- deleted 4y ago[deleted]
- ape4 4y agoThe Linux /etc/group file was my first and incorrect thought.
- jpf0 4y agoGroup is (was) a function in various array languages, including K, APL, BQN, J, and Shakti.
- chrispsn 4y agoGood point - added a simple explanation in the article: Group tells you the places each element occurs in a list. It generates lists of indices.
- nextaccountic 4y agoNice! Sounds useful for scatter and gather algorithms https://en.wikipedia.org/wiki/Gather/scatter_(vector_addressing) https://en.wikipedia.org/wiki/Gather/scatter_(vector_address...
- gdprrrr 4y agoA group is a non-empty set and an operation that combines any two elements of the set to produce a third element of the set, in such a way that the operation is associative, an identity element exists and every element has an inverse. /s
- co_dh 4y agohttps://code.kx.com/q/ref/ https://code.kx.com/q/ref/
- co_dh 4y agoGroup is actually like inverse a mapping. Given an array A which map index to value, group A map value to index. A common idiom is: desc count each group A , which list most frequent element first