[R] Coercing a character zoo to a numeric

[Gabor Grothendieck]

On Tue, Sep 27, 2011 at 5:56 AM, Ashim Kapoor <ashimkapoor at gmail.com> wrote:
> Dear R-helpers,
>
> It seems to me that a character zoo cannot be coerced to a numeric zoo.
> Below is a minimal example. Can someone tell me what I have done wrong?
>
>> z<-zoo(1:4,order.by=1:4)
>> coredata(z)<-as.character(coredata(z))
>> str(z)
> ‘zoo’ series from 1 to 4
>  Data: chr [1:4] "1" "2" "3" "4"
>  Index:  int [1:4] 1 2 3 4
>> coredata(z)<-as.numeric(coredata(z))
>> str(z)
> ‘zoo’ series from 1 to 4
>  Data: chr [1:4] "1" "2" "3" "4"
>  Index:  int [1:4] 1 2 3 4
>
>

See ?zoo where it says that the zoo object may be "a numeric vector,
matrix or a factor".

Thus character is not supported although I suspect that a number of
operations continue to work anyways -- although evidently not that
one.

This seems to result in a numeric zoo object:

aggregate(z, identity, as.numeric)

although these sorts of computations with zoo objects that strictly
speaking are not legal are, of course, not officially supported.

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