explicit_na: Missing data

In tern: Create Common TLGs Used in Clinical Trials

Missing data

Description

Substitute missing data with a string or factor level.

Usage

explicit_na(x, label = default_na_str(), drop_na = default_drop_na())

default_drop_na()

set_default_drop_na(drop_na)

Arguments

x	(factor or character) values for which any missing values should be substituted.
label	(string) string that missing data should be replaced with.
drop_na	(flag) if TRUE and x is a factor, any levels that are only label will be dropped.

Value

x with any NA values substituted by label.

• tern_default_drop_na: (flag)
  default value for drop_na argument in explicit_na().

• tern_default_drop_na has no return value.

Functions

• default_drop_na(): should NA values without a dedicated level be dropped?

• set_default_drop_na(): Setter for default NA value replacement string. Sets the option "tern_default_drop_na" within the R environment.

Examples

explicit_na(c(NA, "a", "b"))
is.na(explicit_na(c(NA, "a", "b")))

explicit_na(factor(c(NA, "a", "b")))
is.na(explicit_na(factor(c(NA, "a", "b"))))

explicit_na(sas_na(c("a", "")))

explicit_na(factor(levels = c(NA, "a")))
explicit_na(factor(levels = c(NA, "a")), drop_na = TRUE) # previous default

tern documentation built on Dec. 18, 2025, 9:07 a.m.