na_values: Get / Set SPSS missing values

Description

Get / Set SPSS missing values

Usage

na_values(x)
na_values(x) <- value
na_range(x)
na_range(x) <- value
set_na_values(.data, ..., .values = NA, .strict = TRUE)
set_na_range(.data, ..., .values = NA, .strict = TRUE)
is_user_na(x)
is_regular_na(x)
user_na_to_na(x)
user_na_to_regular_na(x)
user_na_to_tagged_na(x)

Value

na_values() will return a vector of values that should also be considered as missing. na_range() will return a numeric vector of length two giving the (inclusive) extents of the range.

set_na_values() and set_na_range() will return an updated copy of .data.

Arguments

x: A vector (or a data frame).
value: A vector of values that should also be considered as missing (for na_values) or a numeric vector of length two giving the (inclusive) extents of the range (for na_values, use -Inf and Inf if you want the range to be open ended).
.data: a data frame or a vector
...: name-value pairs of missing values (see examples)
.values: missing values to be applied to the data.frame, using the same syntax as value in na_values(df) <- value or na_range(df) <- value.
.strict: should an error be returned if some labels doesn't correspond to a column of x?

Details

See haven::labelled_spss() for a presentation of SPSS's user defined missing values.

Note that base::is.na() will return TRUE for user defined missing values. It will also return TRUE for regular NA values. If you want to test if a specific value is a user NA but not a regular NA, use is_user_na(). If you want to test if a value is a regular NA but not a user NA, not a tagged NA, use is_regular_na().

You can use user_na_to_na() to convert user defined missing values to regular NA. Note that any value label attached to a user defined missing value will be lost. user_na_to_regular_na() is a synonym of user_na_to_na().

The method user_na_to_tagged_na() will convert user defined missing values into haven::tagged_na(), preserving value labels. Please note that haven::tagged_na() are defined only for double vectors. Therefore, integer haven_labelled_spss vectors will be converted into double haven_labelled vectors; and user_na_to_tagged_na() cannot be applied to a character haven_labelled_spss vector.

tagged_na_to_user_na() is the opposite of user_na_to_tagged_na() and convert tagged NA into user defined missing values.

Examples

Run this code

v <- labelled(c(1,2,2,2,3,9,1,3,2,NA), c(yes = 1, no = 3, "don't know" = 9))
v
na_values(v) <- 9
na_values(v)
v

is.na(v) # TRUE for the 6th and 10th values
is_user_na(v) # TRUE only for the 6th value

user_na_to_na(v)
na_values(v) <- NULL
v
na_range(v) <- c(5, Inf)
na_range(v)
v
user_na_to_na(v)
user_na_to_tagged_na(v)

# it is not recommended to mix user NAs and tagged NAs
x <- c(NA, 9, tagged_na("a"))
na_values(x) <- 9
x
is.na(x)
is_user_na(x)
is_tagged_na(x)
is_regular_na(x)

if (require(dplyr)) {
  # setting value label and user NAs
  df <- tibble(s1 = c("M", "M", "F", "F"), s2 = c(1, 1, 2, 9)) %>%
    set_value_labels(s2 = c(yes = 1, no = 2)) %>%
    set_na_values(s2 = 9)
  na_values(df)

  # removing missing values
  df <- df %>% set_na_values(s2 = NULL)
  df$s2

  # example with a vector
  v <- 1:10
  v <- v %>% set_na_values(5, 6, 7)
  v
  v %>% set_na_range(8, 10)
  v %>% set_na_range(.values = c(9, 10))
  v %>% set_na_values(NULL)
}