What do the %op% operators in mean? For example “%in%”?

Question

I tried to do this simple search but couldn\'t find anything on the percent (%) symbol in R.

What does %in% mean in the following c

Answer 1

%in% is an operator used to find and subset multiple occurrences of the same name or value in a matrix or data frame.

For example 1: subsetting with the same name

set.seed(133)
x <- runif(5)
names(x) <- letters[1:5]
x[c("a", "d")]
#  a         d 
#  0.5360112 0.4231022

Now you change the name of "d" to "a"

 names(x)[4] <- "a"

If you try to extract the similar names and its values using the previous subscript, it will not work. Notice the result, it does not have the elements of [1] and [4].

x[c("a", "a")]

#        a         a 
#    0.5360112 0.5360112 

So, you can extract the two "a"s from different position in a variable by using %in% binary operator.

names(x) %in% "a"
#  [1]  TRUE FALSE FALSE  TRUE FALSE

#assign it to a variable called "vec"
 vec <- names(x) %in% "a"

#extract the values of two "a"s
 x[vec]
 #         a         a 
 #  0.5360112 0.4231022 

Example 2: Subsetting multiple values from a column Refer this site for an example