matching in R

라벨: Informatics
이메일로 전송BlogThis!Twitter에서 공유Facebook에서 공유


va = c('a','x','e')   # query
vb = c('a','b','c','d','e','f','e')   #db


match( va, vb) # not working for multiple match
                        # also use with na.omit()
[1]  1  NA  5
                   

which( vb %in% va)  # db, then query
[1] 1 5 7   <---- this order is not a-x-e, but a-e-x as in db


match considers the order of query item,
but which just returns matched ones in db's order


multiple grep

lapply( c(4,1), function(x) grep(x, c(4,4,1,1,1)))


이메일로 전송BlogThis!Twitter에서 공유Facebook에서 공유

라벨: Informatics