AllDuplicated: Index Vector of All Values Involved in Ties

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AllDuplicatedR Documentation

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).





vector of any type.


logical vector of the same dimension as x.


Andri Signorell <>

See Also

unique returns a unique list of all values in x
duplicated 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 B
intersect returns all elements which appear in A and in B
setdiff(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 B
split(A, A) returns a list with all the tied values in A (see examples)


x <- c(1:10, 4:6)


# compare to:


# 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)

# count elements involved in ties
# count tied groups

DescTools documentation built on Nov. 20, 2023, 5:08 p.m.