Missing Value Handling in Data Frame in R

Tuesday, January 22, 2013

In R, missing values are represented by the symbol NA (not available) . Impossible values (e.g., dividing by zero) are represented by the symbol NaN (not a number). Unlike SAS, R uses the same symbol for character and numeric data.

For example, I want to check how many missing values in Ozone column in Airquality data frame. Let's using table() operation.