why use na column in random forest why add an na column instead of value imputation can you add a na in the dataframe function for random forest why add na column in random forest why use na column in random forest why use na indicator in random forest can an na indicator be used in random forest why is an na indicator column used why add na column why use na indicator what column is an na in random forest why not add an na value when imputating why do na indicator columns have to be added if data is not set in random forest how to append na in random forest why use na indicator is an na value added when i impute what's the function to append na? why is it useful to add a na column instead of a value? why add na in random forest can random forest append nas