sas_na: Convert strings to 'NA'

In tern: Create Common TLGs Used in Clinical Trials

Convert strings to NA

Description

SAS imports missing data as empty strings or strings with whitespaces only. This helper function can be used to convert these values to NAs.

Usage

sas_na(x, empty = TRUE, whitespaces = TRUE)

Arguments

x	(factor or character) values for which any missing values should be substituted.
empty	(flag) if TRUE, empty strings get replaced by NA.
whitespaces	(flag) if TRUE, strings made from only whitespaces get replaced with NA.

Value

x with "" and/or whitespace-only values substituted by NA, depending on the values of empty and whitespaces.

Examples

sas_na(c("1", "", " ", "   ", "b"))
sas_na(factor(c("", " ", "b")))

is.na(sas_na(c("1", "", " ", "   ", "b")))

tern documentation built on June 20, 2025, 9:08 a.m.