[R] Weird Behavior of mean

[CALUM POLWART]

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


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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