heavy rocker dude heavy rocker dude - 1 year ago 42
R Question

What do the %op% operators in mean in R? For example "%in%"

I tried to do this simple search but couldn't find anything on the percent (

) symbol in R. What does
mean in the following code?

time(x) %in% time(y)

are matrices.

How do I look up help on
and similar functions that follow the
pattern, as I cannot locate the help file?

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Answer Source

Put quotes around it to find the help page. Either of these work

> help("%in%")
> ?"%in%"

Once you get to the help page, you'll see that

‘%in%’ is currently defined as

‘"%in%" <- function(x, table) match(x, table, nomatch = 0) > 0’

Since time is a generic, I don't know what time(X2) returns without knowing what X2 is. But, %in% tells you which items from the left hand side are also in the right hand side.

> c(1:5) %in% c(3:8)

See also, intersect

> intersect(c(1:5), c(3:8))
[1] 3 4 5