If trim
is zero (the default), the arithmetic mean of the
values in x
is computed, as a numeric or complex vector of
length one. If x
is not logical (coerced to numeric), numeric
(including integer) or complex, NA_real_
is returned, with a warning.
If trim
is non-zero, a symmetrically trimmed mean is computed
with a fraction of trim
observations deleted from each end
before the mean is computed.