Stavros Macrakis wrote:
Martin,
I agree that global options settings that affect computations are
problematic.
But that's not the issue I was addressing. If for some classes, func.CLASS
has certain defaults for some arguments, it is surprising that for other
classes, it has different defaults, whether these defaults are fixed or
taken from global settings -- when there is no obvious reason for the
default to vary by class.
-s
"A foolish consistency is the hobgoblin of little minds..."
The thing is that if you are converting the classifying factors of a
table to columns of a data frame, you will presumably prefer that they
come out as factors, retaining level order. The alternative is like this:
> (x <- as.table(c("Rare"=5, "Medium"=2, "Well-done"=6)))
Rare Medium Well-done
5 2 6
> df <- as.data.frame(x, stringsAsFactors=F)
> xtabs(Freq~Var1, data=df)
Var1
Medium Rare Well-done
2 5 6
This is completely different from other cases, where as.data.frame will
auto-convert character variables to factors; e.g., on reading. Having a
global option intended for read.table() interfere with the above kind of
operation, could be a really nasty surprise for the user. (Notice also
that the option was introduced in 2.10.0, before then, noone would
expect that classifying factors could come out as non-factors.
Defaulting to the global option could easily break working code.)
--
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
~~~~~~~~~~ - (p.dalga...@biostat.ku.dk) FAX: (+45) 35327907
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