"2007-04-07" "2007-05-21"
Next with D, I then go back and find out the positions of the
elements in D within A. And then use the result as an index vector
into the vector of observations (which is not shown here) I feel
sure I am doing it the stupid way (or the procedural
<- function(x, n = 1) head(x, n)
> aggregate(z, ave(time(z), as.yearmon(time(z)), FUN = head1), head1)
>
>
> For more on zoo try:
>
> library(zoo)
> vignette("zoo")
>
> and also read the Help Desk article in R News 4/1 about dates.
>
>
>
> On 5/27
