Clean up factor levels

This utility function drops empty factor levels from target factors as well as converting them to factors from character variables.

Usage

epict_clean_factors(obs, vars = c())

Arguments

obs

A data.frame with at least one character or factor variable.

vars

A character vector of variables. Defaults to empty.

Value

A data.table with empty factors dropped and character vectors transformed to factors as specified.

See also

Preprocessing functions epict_check_obs(), epict_check_raw_obs(), epict_drop_na_ct(), epict_filter_ids(), epict_flag_spurious_obs(), epict_make_time_rel_to_first_uncensored(), epict_make_time_rel()

Author

Sam Abbott

Examples

obs <- data.frame(
 m = c("fa", "aefwe", "efe"),
 c = factor(c("fa", "asas", "asa"), levels = c("fa"))
)
summary(obs)
#>       m                c    
#>  Length:3           fa  :1  
#>  Class :character   NA's:2  
#>  Mode  :character           

# Default without specifying variables
summary(epict_clean_factors(obs))
#>       m                c    
#>  Length:3           fa  :1  
#>  Class :character   NA's:2  
#>  Mode  :character           

# Specify variables
summary(epict_clean_factors(obs, vars = c("m", "c")))
#>      m        c    
#>  aefwe:1   fa  :1  
#>  efe  :1   NA's:2  
#>  fa   :1