Patrick Burns wrote: > If the sentence in question were amended to: > > Values of trim outside that range ... > > then I think it would rule out the misinterpretation of > the sentence.
Yup. And I maintain that although the wording may not be technically ambiguous, the whole operation is about restricting the range of x, and therefore is easy to interpolate "the range of x after trimming from each end". > > Pat > > > Prof Brian Ripley wrote: > >> There is only one _range_ mentioned, (0, 0.5). I don't see how you >> can construe 'that range' to be a reference to anything other than >> (0, 0.5). >> >> And why do you suppose the description for argument 'trim' is >> referring to 'values' of a different argument? >> >> It is telling you what happens for values of trim < 0 or > 0.5: that >> is not information that it is appropriate to excise. >> >> >> On Thu, 25 Oct 2007, Peter Dalgaard wrote: >> >> >> >>> Liaw, Andy wrote: >>> >>>> (I see this in both R-patched r43124 and R-devel r43233.) >>>> In the Argument section of ?mean: >>>> >>>> trim the fraction (0 to 0.5) of observations to be trimmed from >>>> each >>>> end of x before the mean is computed. Values outside that range are >>>> taken as the nearest endpoint. >>>> >>>> Then in the Value section: >>>> >>>> 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. >>>> >>>> The description in "trim" to me sounds like Windsorizing, rather than >>>> trimming. Should that be edited? >>>> >>>> >>>> >>> I think so: >>> >>> >>>> x <- sort(rnorm(10)) >>>> mean(x,trim=.1) >>>> >>> [1] -0.6387413 >>> >>>> mean(x[2:9]) >>>> >>> [1] -0.6387413 >>> >>>> mean(x[c(2,2:9,9)]) # Winsorizing >>>> >>> [1] -0.6204222 >>> >>> So yes, it is trimming, not Winsorizing, and the last sentence in the >>> description of "trim" is misleading and should be, well..., trimmed. >>> >>> >>> >> >> >> -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
