utility function to identify variables with one value only.
util_check_one_unique_value(x)
logical(1): TRUE, if -- except NA -- exactly only one value
is observed in x
,
FALSE otherwise
vector with values
Other robustness_functions:
util_as_valid_missing_codes()
,
util_correct_variable_use()
,
util_empty()
,
util_ensure_character()
,
util_ensure_in()
,
util_ensure_suggested()
,
util_expect_scalar()
,
util_fix_rstudio_bugs()
,
util_is_integer()
,
util_is_numeric_in()
,
util_is_valid_missing_codes()
,
util_match_arg()
,
util_observations_in_subgroups()
,
util_only_NAs()
,
util_stop_if_not()
,
util_warn_unordered()