[R] Zoo series to a date time stamp that is regular

Gabor Grothendieck ggrothendieck at gmail.com
Tue Jun 29 00:05:41 CEST 2010


On Mon, Jun 28, 2010 at 5:52 PM, stephen sefick <ssefick at gmail.com> wrote:
> Gabor,
> This is very close, but it interpolates values that do not exist in
> the original series.  Is there a way to just "snap" the series to a
> grid without interpolating?
>

Just round up or down the times with trunc.  Using z from my prior
post this rounds up to the next 10 minute boundary.  (If there are
multiple data values in a 10 minute interval it takes the last value.)

min10 <- times("00:10:00")
halfsec <- times("00:00:01")/2
aggregate(z, trunc(time(z) + as.numeric(min10 - halfsec), min10),
function(x) tail(x, 1))


If there is only data value in each 10 minute interval this will round
it up.  If there are multiple data values in an interval it it takes
the last one.



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