Count all observed factor levels, also those that aren't observed...

R: factor levels, recode rest to 'other'...

modification of code to bulk process in r...

Replacing levels of multiple factors...

Looping through levels of a factor and comparing one variable to another...

Rename levels of factors that contain symbols in R...

droplevels() messes with table() so as to produce wrong counts...

Remove rows where a level of a factor occurs only one time in a data.frame in R...

Consecutive value after and new level of factor in R...

split column into three columns based on the under score "_" in the levels...

Counting values within levels...

access second level of list...

R: "Binning" categorical variables...

Ghost factor levels in R...

Select row by level of a factor...

modify name and number of levels for factors within a list...

How to sort factor levels in a table output in R?...

Merging several factor variables...

Unspecified levels in factor()...

How to order levels in a variable based on both the sum of value in a variable and the levels in ano...

R: How to write a function that gets the levels of column in a data.table...

How to deal with overlapping factor levels? (e.g. when producing tables and plots)...

Unused factor levels not dropped after subsetting?...

Best way to make factor levels uniform over a number of data frames...

Shuffle/permute values within specific columns, for a specific factor level of group-variable...

R data frame factor levels...

How to continue to use factor where one level is missing (has been removed)?...

Reorder levels of factor names in data frame...

Replace unwanted values of factor level with NA...

R grouping data with factors and levels...