haven: tagged_na – R documentation

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tagged_na

"Tagged" missing values

Description

"Tagged" missing values work exactly like regular R missing values except that they store one additional byte of information a tag, which is usually a letter ("a" to "z"). When by loading a SAS and Stata file, the tagged missing values always use lower case values.

Usage

tagged_na(...)

na_tag(x)

is_tagged_na(x, tag = NULL)

format_tagged_na(x, digits = getOption("digits"))

print_tagged_na(x, digits = getOption("digits"))

Arguments

`...`	Vectors containing single character. The letter will be used to "tag" the missing value.
`x`	A numeric vector
`tag`	If `NULL`, will only return true if the tag has this value.
`digits`	Number of digits to use in string representation

Details

format_tagged_na() and print_tagged_na() format tagged NA's as NA(a), NA(b), etc.

Examples

x <- c(1:5, tagged_na("a"), tagged_na("z"), NA)

# Tagged NA's work identically to regular NAs
x
is.na(x)

# To see that they're special, you need to use na_tag(),
# is_tagged_na(), or print_tagged_na():
is_tagged_na(x)
na_tag(x)
print_tagged_na(x)

# You can test for specific tagged NAs with the second argument
is_tagged_na(x, "a")

# Because the support for tagged's NAs is somewhat tagged on to R,
# the left-most NA will tend to be preserved in arithmetic operations.
na_tag(tagged_na("a") + tagged_na("z"))

haven

Import and Export 'SPSS', 'Stata' and 'SAS' Files

v2.4.1

MIT + file LICENSE

Authors

Hadley Wickham [aut, cre], Evan Miller [aut, cph] (Author of included ReadStat code), RStudio [cph, fnd]

Initial release