an object containing the values whose weighted mean is to be
a numerical vector of weights the same length as x giving
the weights to use for elements of x.
arguments to be passed to or from methods.
a logical value indicating whether NA
values in x should be stripped before the computation proceeds.
For the default method, a length-one numeric vector.
This is a generic function and methods can be defined for the first
argument x: apart from the default methods there are methods
for the date-time classes "POSIXct", "POSIXlt",
"difftime" and "Date". The default method will work for
any numeric-like object for which [, multiplication, division
and sum have suitable methods, including complex vectors.
If w is missing then all elements of x are given the
same weight, otherwise the weights coerced to numeric by
as.numeric and normalized to sum to one (if possible: if
their sum is zero or infinite the value is likely to be NaN).
Missing values in w are not handled specially and so give a
missing value as the result. However, zero weights are handled
specially and the corresponding x values are omitted from the