R-alpha: var() and missing

[Thomas Lumley]

var() handles missing values in a very strange way. It is not what the
documentation says
> var(c(NA,1:10))
[1] 0
> var(1:10)
[1] 9.166667
This is because sum() handles NA incorrectly
> sum(NA)
[1] 0
> sum(NA,na.rm=T)
[1] 0
> sum(NA,na.rm=F)
[1] 0

Also the documentation gives a pairwise= option to var() which isn't in
the function.


Thomas Lumley
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