Zablone Owiti
2010-May-12 03:10 UTC
[R] How to extract sum of particular months in a monthly data series
Dear Users, I have a monthly data for a number of years(1960-2007) for a number of stations and i wish to extract sesonal time-series for the months of March-May and October-November for very station. I have read this data with read.table in R with stations as columns and time (months) as rows. My attempt to aggregate with the zoo package using the function as.yearqtr failed since this sums evey three months of the year from January. Is there away it can be coersed to aggregate particular months as in my case? Thanks ---------------------------- ZABLONE OWITI GRADUATE STUDENT College of Atmospheric Science Nanjing University of Information, Science and Technology Add: 219 Ning Liu Rd, Nanjing, Jiangsu, 21004, P.R. China Tel: +86-25-58731402 Fax: +86-25-58731456 Mob. 15077895632 Website: www.nuist.edu.cn =================================================== [[alternative HTML version deleted]]
Gabor Grothendieck
2010-May-12 11:13 UTC
[R] How to extract sum of particular months in a monthly data series
Try this:
library(zoo)
z <- as.zoo(AirPassengers)
time(z) <- as.yearmon(time(z))
ix <- cycle(as.ts(z)) %in% c(3:5, 10:11)
aggregate(z[ix], floor, sum)
or this:
ix <- format(time(z), "%m") %in% c("03", "04",
"05", "10", "11")
aggregate(z[ix], floor, sum)
It would be best if next time you posted some sample data.
On Tue, May 11, 2010 at 11:10 PM, Zablone Owiti <zowiti at ncst.go.ke>
wrote:> Dear Users,
>
> I have a monthly data for a number of years(1960-2007) for a number of
> stations and i wish to extract sesonal time-series for the months of
> March-May and October-November for very station. I have read this data with
> read.table ?in R with stations as columns and time (months) as rows. My
> attempt to aggregate with the zoo package using the function as.yearqtr
> failed since this sums evey three months of the year from January. Is there
> away it can be coersed to aggregate particular months as in my case?
>
> Thanks
>
> ----------------------------
> ?ZABLONE OWITI
> ?GRADUATE STUDENT
> College of Atmospheric Science
> Nanjing University of Information, Science and Technology
> Add: 219 Ning Liu Rd, Nanjing, Jiangsu, 21004, P.R. China
> ?Tel: +86-25-58731402
> Fax: +86-25-58731456
> Mob. 15077895632
> Website: ?www.nuist.edu.cn
> ===================================================>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
Zablone Owiti
2010-May-12 12:35 UTC
[R] How to extract sum of particular months in a monthly data series
Thanks Dr. Gabor, the commands you gave worked.
----------------------------
ZABLONE OWITI
GRADUATE STUDENT
College of Atmospheric Science
Nanjing University of Information, Science and Technology
Add: 219 Ning Liu Rd, Nanjing, Jiangsu, 21004, P.R. China
Tel: +86-25-58731402
Fax: +86-25-58731456
Mob. 15077895632
Website: www.nuist.edu.cn
===================================================
----------------------------------------
From: "Gabor Grothendieck" <ggrothendieck@gmail.com>
Sent: Wednesday, May 12, 2010 7:15 PM
To: zowiti@ncst.go.ke
Subject: Re: [R] How to extract sum of particular months in a monthly data
series
Try this:
library(zoo)
z <- as.zoo(AirPassengers)
time(z) <- as.yearmon(time(z))
ix <- cycle(as.ts(z)) %in% c(3:5, 10:11)
aggregate(z[ix], floor, sum)
or this:
ix <- format(time(z), "%m") %in% c("03", "04",
"05", "10", "11")
aggregate(z[ix], floor, sum)
It would be best if next time you posted some sample data.
On Tue, May 11, 2010 at 11:10 PM, Zablone Owiti wrote:> Dear Users,
>
> I have a monthly data for a number of years(1960-2007) for a number of
> stations and i wish to extract sesonal time-series for the months of
> March-May and October-November for very station. I have read this data
with> read.table in R with stations as columns and time (months) as rows. My
> attempt to aggregate with the zoo package using the function as.yearqtr
> failed since this sums evey three months of the year from January. Is
there> away it can be coersed to aggregate particular months as in my case?
>
> Thanks
>
> ----------------------------
> ZABLONE OWITI
> GRADUATE STUDENT
> College of Atmospheric Science
> Nanjing University of Information, Science and Technology
> Add: 219 Ning Liu Rd, Nanjing, Jiangsu, 21004, P.R. China
> Tel: +86-25-58731402
> Fax: +86-25-58731456
> Mob. 15077895632
> Website: www.nuist.edu.cn
> ===================================================>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]