R FAQ How does R handle missing values?
Like other statistical software packages, R is capable of handling missing values. However, to those accustomed to working with missing values in other packages, the way in which R handles missing values may require a shift in thinking. On this page, we will present first the basics of how missing values are represented in R. Next, for those coming from SAS, SPSS, and/or Stata, we will outline some of the differences between missing values in R and missing values elsewhere. Finally, we will introduce some of the tools for working with missing values in R, both in data management and analysis.