Hmisc (version 2.2-0)

.in.: Find Matching (or Non-Matching) Elements

Description

For two vectors or scalars a and b, a %in% b returns a vector of logical values corresponding to the elements in a. A value is TRUE if that element of a is found somewhere in b, FALSE otherwise. If a is a factor object and b is numeric, converts a to its integer codes before the comparison. If a is numeric and b is factor, converts b to codes. %nin% returns TRUE if the element in a is not in b.

Usage

a %in% b
a %nin% b

Arguments

a

a vector (numeric, character, factor)

b

a vector (numeric, character, factor), matching the mode of a

Value

• vector of logical values with length equal to length of a.

See Also

match

Examples

w <- factor(c("a","b","c"))
w %in% c("b","c")
w %in% c(2,3)      #same as previous, but with warning


#Suppose that a variable x has levels "a", "b1", "b2" and you
#want to classify levels "b1" and "b2" as just "b".  You can use
#the \%in\% operator and do the following:
# levels(x)[levels(x) \%in\% c("b1","b2")] <- "b"
#Note that levels(x) <- list(b=c('b1','b2')) would be a better approach