[R] Help with data containing date

[Gabor Grothendieck]

Try this:

Lines <- "Date             A    B        C       D           E
 1978-10-22   18  20.64   0.0   0.176     -1.76
 1978-10-23   15  17.06   0.4   0.147      2.52
 1978-10-24    3   7.588   0.0   0.068     -6.86
 1978-10-25    9  11.491   0.0   0.102    -1.01
 1978-10-26   13  14.98   1.4    0.130     1.26 "

library(zoo); library(chron)
z <- read.zoo(textConnection(Lines), header = TRUE, FUN = as.chron)
aggregate(z, months, mean)
aggregate(z, years, mean)

chron was used above to take advantage of the convenient months()
and years() functions that are available for it although it could be
done using Date class with only slightly more complexity:

library(zoo)
z <- read.zoo(textConnection(Lines), header = TRUE)
aggregate(z, format(time(z), "%m"), mean)
aggregate(z, format(time(z), "%Y"), mean)

Read the three zoo vignettes and the article on dates in R News 4/1 as well
as the references to that article.

On Tue, Sep 8, 2009 at 11:23 PM, Subodh Acharya<shoebodh at gmail.com> wrote:
> Hello Everyone,I think this is a very simple problem, I have been struggling
> with it for a few days now.
> I have a 10-year daily data  in the following format.
>
>
>  Date             A    B        C       D           E
>  1978-10-22   18  20.64   0.0   0.176     -1.76
>  1978-10-23   15  17.06   0.4   0.147      2.52
>  1978-10-24    3   7.588   0.0   0.068     -6.86
>  1978-10-25    9  11.491   0.0   0.102    -1.01
>  1978-10-26   13  14.98   1.4    0.130     1.26
>
> I want to calculate the monthly and Annual average averages of A, B, C, D,
> and E, for the 10 years.
>
> I tried to use the xts package to convert the data into a time series object
> but was not able to even change it into the time series object.
> Any help would be highly appreciated
>
> Thank you in advance.
>
> --
> Subodh Acharya
> University of Florida
> Gainesville, FL.
>
>        [[alternative HTML version deleted]]
>
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