R help - Nov 2008 - Reshape with var as fun.aggregate

I used to be able to use variance for fun.aggregate, but since I 
upgraded from R 2.6 to 2.7 (Ubuntu hardy to intrepid), it no longer 
works.
> library("reshape")
> data("french_fries")
> ffm <- melt(french_fries, id=1:4, na.rm = TRUE)
> cast(ffm, rep ~ treatment, length)
  rep   1   2   3
1   1 579 578 575
2   2 580 579 580
> cast(ffm, rep ~ treatment, mean)
  rep        1        2        3
1   1 3.207772 3.177336 3.024522
2   2 3.181207 3.115544 3.277759
> cast(ffm, rep ~ treatment, var)
Error in fun.aggregate(data$value[0]) : 'x' is empty

Any ideas?

Hi Jason,

The reason you are getting this error is that the latest version of
reshape uses fun.aggregate(numeric(0)) to figure out what missing
values should be filled in with.  Unfortunately there was a brief
period in R versions when var(numeric(0)) returned an error rather
than a missing value.  You can work around the problem by manually
specifying fill = NA.

Regards,

Hadley

On Wed, Nov 26, 2008 at 1:05 PM,  <locklin.jason at gmail.com>
wrote:
> I used to be able to use variance for fun.aggregate, but since I
> upgraded from R 2.6 to 2.7 (Ubuntu hardy to intrepid), it no longer
> works.
>
>> library("reshape")
>> data("french_fries")
>> ffm <- melt(french_fries, id=1:4, na.rm = TRUE)
>> cast(ffm, rep ~ treatment, length)
>  rep   1   2   3
> 1   1 579 578 575
> 2   2 580 579 580
>> cast(ffm, rep ~ treatment, mean)
>  rep        1        2        3
> 1   1 3.207772 3.177336 3.024522
> 2   2 3.181207 3.115544 3.277759
>> cast(ffm, rep ~ treatment, var)
> Error in fun.aggregate(data$value[0]) : 'x' is empty
>
> Any ideas?
>
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