Index Vector of All Values Involved in Ties
The function duplicated returns a logical vector indicating which elements x are duplicates, but will not include the very first appearance of subsequently duplicated elements. AllDuplicated returns an index vector of ALL the values in x which are involved in ties.
So !AllDuplicated can be used to determine all elements of x, which
appear exactly once (thus with frequency 1).
AllDuplicated(x)
x |
vector of any type. |
logical vector of the same dimension as x.
Andri Signorell <andri@signorell.net>
unique returns a unique list of all values in xduplicated returns an index vector flagging all elements, which appeared more than once (leaving out the first appearance!)union(A, B) returns a list with the unique values from A and Bintersect returns all elements which appear in A and in Bsetdiff(A, B) returns all elements appearing in A but not in B setequal(A, B) returns TRUE if A contains exactly the same elements as Bsplit(A, A) returns a list with all the tied values in A (see examples)
x <- c(1:10, 4:6) AllDuplicated(x) # compare to: duplicated(x) x[!AllDuplicated(x)] # union, intersect and friends... A <- c(sort(sample(1:20, 9)),NA) B <- c(sort(sample(3:23, 7)),NA) # all elements from A and B (no duplicates) union(A, B) # all elements appearing in A and in B intersect(A, B) # elements in A, but not in B setdiff(A, B) # elements in B, but not in A setdiff(B, A) # Does A contain the same elements as B? setequal(A, B) # Find ties in a vector x x <- sample(letters[1:10], 20, replace=TRUE) ties <- split(x, x) # count tied groups sum(sapply(ties, length) > 1) # length of tied groups (x <- sapply(ties, length))[x>1] # by means of table tab <- table(x) tab[tab>1] # count elements involved in ties sum(tab>1) # count tied groups sum(tab[tab>1])
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