%vin% {validate}R Documentation

A consistent set membership operator

Description

A membership operator like %in% that handles NA more consistently with R's other logical comparison operators.

Usage

x %vin% table

Arguments

x

vector or NULL: the values to be matched

table

vector or NULL: the values to be matched against.

Note

R's basic comparison operators (almost) always return NA when one of the operands is NA. The %in% operator is an exception. Compare for example NA %in% NA with NA == NA.

Examples

# we cannot be sure about the first element:
c(NA, "a") %vin% c("a","b")

# we cannot be sure about the 2nd and 3rd element (but note that they
# cannot both be TRUE):
c("a","b","c") %vin% c("a",NA)

# we can be sure about all elements:
c("a","b") %in% character(0)
[Package validate version 0.2.4 Index]