[R] Weird Behavior of mean

[Martin Maechler]

>>>>> CALUM POLWART 
>>>>>     on Fri, 13 Dec 2024 08:56:15 +0000 writes:

    > I've not checked the code, but I think that result would
    > happen if mean uses something like

    > if (na.rm == TRUE) { # do something to remove the NA's }

    > And as uses something like

    > If (na.rm != FALSE) { # do something to remove the NA's }

    > Or perhaps ever na.rm == T

Hey, "be careful you are insulting" (;-) R core code would *never* contain stupid silly code 
such as   <logical> == TRUE 


> fortunes :: fortune("TRUE.*TRUE", fixed=FALSE)

Ted Harding: But you can also do these with 'any' and 'all', e.g. any(v==TRUE).
Thomas Lumley: or any( (v==TRUE)==TRUE), or any( ((v==TRUE)==TRUE)==TRUE)... Or, perhaps, any(v). Lewis Carroll wrote a nice piece
on this theme.
   -- Ted Harding and Thomas Lumley (about implementing an 'or' of a logical vector)
      R-help (August 2004)

It uses  if(isTRUE(na.rm))
and yes,
people using  T  for TRUE  are "selber tschuld" (Swiss German for "your fault!")

Martin


    > If you ever see posts from Bert on here with T and F, he
    > is hard core thorough and uses full words for exactly this
    > reason, someone can reassign F as True if they want and
    > your code will melt!

    > On Fri, 13 Dec 2024, 08:31 Ivo Welch,
    > <ivo.welch using gmail.com> wrote:

    >> Is the following a strange behavior for `mean` vs. `sd` ?
    >> 
    >> ``` $ R --vanilla. ## 4.4.2 > x=c(NA,1,2,3) > c(
    >> mean(x,na.rm=T), sd(x,na.rm=T) ) [1] 2 1 > T=20 ## bad
    >> idea for a parameter.  T is also used for TRUE > c(
    >> mean(x,na.rm=T), sd(x,na.rm=T) ) [1] NA 1
    >> >
    >> ```
    >> 
    >> This one was a baffler for me to track down for a few
    >> hours...
    >> 
    >> ______________________________________________
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    > ______________________________________________
    > R-help using r-project.org mailing list -- To UNSUBSCRIBE and
    > more, see https://stat.ethz.ch/mailman/listinfo/r-help
    > PLEASE do read the posting guide
    > https://www.R-project.org/posting-guide.html and provide
    > commented, minimal, self-contained, reproducible code.