R help - Nov 2005 - [<- and indexing for zoo objects

Hi
 
I've been greatly enjoying the functionality the zoo package offers.
However I've hit a snag with the following code
 
> a <- zoo(matrix(1:10,5,2), 2001:2005)
> a
          
2001  1  6
2002  2  7
2003  3  8
2004  4  9
2005  5 10
> a[I(2003), 2]
      
2003 8
> a[I(2003), 2] <- NA
Error: subscript out of bounds
> 
I've also tried
 
> coredata(a[I(2003), 2]) <- NA
Error: subscript out of bounds
> 
 
but that doesn't work either.  I can of course do
 
> ix <- which(index(a)==2003)
> a[ix, 2] <- NA
> a
          
2001  1  6
2002  2  7
2003  3 NA
2004  4  9
2005  5 10
> 
which gives me the desired result but I feel that a timeseries class should
really be able to handle the first syntax since with the workaround I'm back
to the way of doing things before I had timeseries objects.
 
Am I missing something or any comments?
 

Regards

Tobias Brandt
 

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Tobias,

thanks for the report:
> > a[I(2003), 2] <- NA
> Error: subscript out of bounds
Yes, we would have to write a [<-.zoo method for that, currently we
rely on the corresponding methods for matrices and vectors. I'll add it
to the WISHLIST and try to add this functionality for the next zoo
release.

All the indexing can also be done via window<-

window(a, start = 2003, end = 2003)[,2] <- NA

which would currently be the preferred solution.

thx,
Z

On 11/14/05, Brandt, T. (Tobias) <TobiasBr at taquanta.com>
wrote:
>
>
> Hi
>
> I've been greatly enjoying the functionality the zoo package offers.
> However I've hit a snag with the following code
>
> > a <- zoo(matrix(1:10,5,2), 2001:2005)
> > a
>
> 2001  1  6
> 2002  2  7
> 2003  3  8
> 2004  4  9
> 2005  5 10
> > a[I(2003), 2]
>
> 2003 8
> > a[I(2003), 2] <- NA
> Error: subscript out of bounds
> >
>
> I've also tried
>
> > coredata(a[I(2003), 2]) <- NA
> Error: subscript out of bounds
> >
>
> but that doesn't work either.  I can of course do

Try this:

   window(a, 2003)[,2] <- NA

See

   ?"window<-.zoo"

for more info.