Missing values are represented in R with the general symbol
NA. They can be inserted in almost all data containers: all
atomic vectors except raw vectors can contain missing values. To
achieve this, R automatically converts the general NA symbol
to a typed missing value appropriate for the target vector. The
objects provided here are aliases for those typed NA
objects.
Usage
na_lgl
na_int
na_dbl
na_chr
na_cpl
Arguments
Format
An object of class logical of length 1.
Details
Typed missing values are necessary because R needs sentinel values
of the same type (i.e. the same machine representation of the data)
as the containers into which they are inserted. The official typed
missing values are NA_integer_, NA_real_,
NA_character_ and NA_complex_. The missing value for
logical vectors is simply the default NA. The aliases
provided in rlang are consistently named and thus simpler to
remember. Also, na_lgl is provided as an alias to NA
that makes intent clearer.
Since na_lgl is the default NA, expressions such as
c(NA, NA) yield logical vectors as no data is available to
give a clue of the target type. In the same way, since lists and
environments can contain any types, expressions like
list(NA) store a logical NA.
See Also
The along family to create typed vectors
filled with missing values.
typeof(NA)
typeof(na_lgl)
typeof(na_int)
# Note that while the base R missing symbols cannot be overwritten,# that's not the case for rlang's aliases:na_dbl <- NAtypeof(na_dbl)