Try aggregate:
Lines <- "Year Month Hour co2 num1 num2
2006 11 0 383.3709 28 28
2006 11 1 383.3709 28 28
2006 11 2 383.3709 28 28
2006 11 3 383.3709 28 28
2006 11 4 383.3709 28 28
2006 11 5 383.3709 28 28
2006 11 6 383.3709 28 28
2006 11 7 383.3709 28 28
2006 11 8 383.3709 28 28
2006 11 9 383.3709 27 27
2006 11 10 383.3709 28 28
"
DF <- read.table(textConnection(Lines), header = TRUE)
aggregate(DF[4:6],
with(DF, data.frame(Year, Qtr = (Month - 1) %/% 3 + 1, Hour)),
mean)
On Dec 1, 2007 3:57 PM, Sherri Heck <sheck at ucar.edu>
wrote:> Hi all-
>
> I have a dataset (year, month, hour, co2(ppm), num1,num2)
>
>
> [49,] 2006 11 0 383.3709 28 28
> [50,] 2006 11 1 383.3709 28 28
> [51,] 2006 11 2 383.3709 28 28
> [52,] 2006 11 3 383.3709 28 28
> [53,] 2006 11 4 383.3709 28 28
> [54,] 2006 11 5 383.3709 28 28
> [55,] 2006 11 6 383.3709 28 28
> [56,] 2006 11 7 383.3709 28 28
> [57,] 2006 11 8 383.3709 28 28
> [58,] 2006 11 9 383.3709 27 27
> [59,] 2006 11 10 383.3709 28 28
>
> that repeats in this style for each month. I would like to compute the
> mean for each hour in three month intervals.
> i.e. average all 2pms for each day for months march, april and may. and
> then do this for each hour interval.
> i have been messing around with 'for loops' but can't seem to
get the
> output I want.
>
> thanks in advance for any help-
>
> s.heck
> CU, Boulder
>
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