Check if a variable only contains a single value

Source: R/isSingular.R, R/isEmpty.R

A checkFunction that checks if v only contains a single unique value, aside from missing values. This function is intended for use as a precheck in makeDataReport.

isSingular(v)

isEmpty(v)

Arguments

v

A variable (vector) to check. All variable types are allowed.

Value

A checkResult with three entires: $problem (a logical indicating whether v contains only one value), $message (if a problem was found, a message describing which single value the variable takes and how many missing observations it contains, otherwise ""), and $problemValues (always NULL).

See also

check, allCheckFunctions, checkFunction, checkResult

Examples

singularVar <- c(rep("a", 10), NA, NA)
notSingularVar <- c("a", "a", "b", "c", "d", "e", "f", NA, NA)

isSingular(singularVar)
#> The variable only takes one (non-missing) value: a. The variable contains 16.67 \% missing observations.
isSingular(notSingularVar)
#> No problems found.