[R] splitting time vector into days

Greetings -- I have a dataframe a with one element a vector, time, of POSIXct values. What's a good way to split the data frame into periods of a$time, e.g. days, and apply a function, e.g. mean, to some other column of the dataframe, e.g. a$value? Cheers, Alexy

Re: [R] splitting time vector into days

?aggregate ?window.zoo ?rollapply anyway have a look at package zoo On Tue, Sep 9, 2008 at 3:25 PM, Alexy Khrabrov [EMAIL PROTECTED] wrote: Greetings -- I have a dataframe a with one element a vector, time, of POSIXct values. What's a good way to split the data frame into periods of a$time,

Re: [R] splitting time vector into days

Here is one way of doing it: x - data.frame(dates=seq(as.POSIXct('2008-09-08'), by='7 hours', length=10), + values=1:10) # split into days x.s - split(x, format(x$dates, %Y%m%d)) x.s $`20080908` dates values 1 2008-09-08 00:00:00 1 2 2008-09-08 07:00:00 2 3