nlevels                 package:base                 R Documentation

The Number of Levels of a Factor

Description:

     Return the number of levels which its argument has.

Usage:

     nlevels(x)

Arguments:

       x: an object, usually a factor.

Details:

     If the argument is not a `factor', `NA' is returned.

     The actual factor levels (if they exist) can be obtained with the
     `levels' function.

Examples:

     nlevels(gl(3,7)) # = 3

