funprog (Higher Order Functions)
http://www.johnmyleswhite.com/notebook/2010/09/23/higher-order-functions-in-r/
https://mitpress.mit.edu/sites/default/files/sicp/full-text/book/book.html
다른 Function을 argument로 사용하는 Function을 higher order function이라고 한다.
- Reduce
- Filter
- Map
- Find
- Position
- Negate
Reduce
Negate
List에서 NULL인 원소 제거하기
LL <- list( "sixx", NULL, NULL, c(21,32,11), TRUE, 16) names(LL) <- seq_along(LL) Filter(Negate(is.null), LL) LL[sapply(LL, is.null)] <- NULL
