[R] summing 15 minute precip data to daily

[Gabor Grothendieck]

On Thu, Feb 17, 2011 at 3:39 PM, Stephen Sefick <ssefick at gmail.com> wrote:
> Janet:
>
> The zoo package and aggregate.zoo should do the trick.  I have done this
> many times with these tools.

Here is some code. Suppose precip is the data.  We convert it to a zoo
object with date/times assuming the first one is at the start of
2000-01-01.  Then we aggregate them by day:

> library(zoo)
> library(chron)
> precip <- 1:200 # sample data
> z <- zooreg(precip, start = as.chron("2000-01-01 00:00:00"), freq = 96)
> z.ag <- aggregate(z, as.Date)
> z.ag
2000-01-01 2000-01-02 2000-01-03
      4656      13872       1572


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