an object for which a method has been defined, or a
numeric vector containing the values whose median is to be computed.

na.rm

a logical value indicating whether NA
values should be stripped before the computation proceeds.

…

potentially further arguments for methods; not used in
the default method.

Value

The default method returns a length-one object of the same type as
x, except when x is logical or integer of even length,
when the result will be double.

If there are no values or if na.rm = FALSE and there are NA
values the result is NA of the same type as x (or more
generally the result of x[FALSE][NA]).

Details

This is a generic function for which methods can be written. However,
the default method makes use of is.na, sort and
mean from package base all of which are generic, and so
the default method will work for most classes
(e.g., "Date") for which a median is a reasonable
concept.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
The New S Language.
Wadsworth & Brooks/Cole.