the fraction (0 to 0.5) of observations to be
trimmed from each end of x before the mean is computed.
Values of trim outside that range are taken as the nearest endpoint. Default is 0 for robust=FALSE and 0.2 for robust=TRUE
robust
logical, determining whether the robust or the convential range should be returned.
na.rm
a logical value indicating whether NA
values should be stripped before the computation proceeds.
...
the dots are sent to RobRange and can be used to set fac (See details).
Value
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.
Details
The R base function range returns the minimum and maximum value of a numeric object. Here we return the span of a (possibly trimmed) numeric vector, say the difference of maximum and minimum value.
If robust is set to TRUE the function determines the trimmed mean m and then the "upper trimmed mean" s of absolute deviations
from m, multiplied by fac (fac is 3 by default). The robust minimum is then defined as m-fac*s or min(x),
whichever is larger, and similarly for the maximum.