[R] Condition warning: has length > 1 and only the first element will be used

[Peter Dalgaard]

Joe Kaser wrote:
> Thanks for the help. ifelse does the job. 
> Could you elaborate, or give an example of the "awkward" things ifelse 
> might do to classed objects?
>

It strips the class. One thing that usually gets me is this:

 > dd <- as.Date(c("2008-1-2","2007-3-21"))
 > ifelse(dd>as.Date("2008-1-1"),dd+7,dd)
[1] 13887 13593
 > dd
[1] "2008-01-02" "2007-03-21"
 > dd+7
[1] "2008-01-09" "2007-03-28"

(Actually, the result gets the attributes of the _condition_, which is 
usually no help at all.)

-- 
    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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