Hi Roslina,
Extending Rui's solution if you want only the last two digits for Year.
agg_dt1$Tahun<-as.numeric(gsub("\\d{2}(\\d+)","\\1",agg_dt1$Tahun))
head(agg_dt1)
# Tahun Bahun x
#1 98 1 607
#2 99 1 814
#3 0 1 580
#4 98 2 1006
#5 99 2 941
#6 0 2 1075A.K.
----- Original Message -----
From: Rui Barradas <ruipbarra...@sapo.pt>
To: arun <smartpink...@yahoo.com>
Cc: Roslina Zakaria <zrosl...@yahoo.com>; R help <r-help@r-project.org>
Sent: Saturday, October 6, 2012 7:22 AM
Subject: Re: [R] arrange data
Hello,
Using Arun's data example, instead of creating a factor "convert" to 4
digits years.
set.seed(1)
dat1 <- data.frame(Tahun=rep(c(98:99,00),each=36),
Bahun=rep(rep(1:12,times=3),each=3),
x=sample(1:500,108,replace=TRUE))
dat2 <- dat1 # operate on a copy
dat2$Tahun <- with(dat2, ifelse(Tahun < 71, 2000 + Tahun, 1900 + Tahun))
agg_dt1 <- aggregate(x=dat2[,3],by=dat2[,c(1,2)],FUN=sum)
head(agg_dt1)
Hope this helps,
Rui Barradas
Em 06-10-2012 03:38, arun escreveu:
> Hi,
>
> I hope this helps you.
> I created a small dataset: 3 replications per month for 1998:2000.
>
> set.seed(1)
> dat1<-data.frame(Tahun=rep(c(98:99,00),each=36),Bahun=rep(rep(1:12,times=3),each=3),
> x=sample(1:500,108,replace=TRUE))
> dat2<-within(dat1,{Tahun<-factor(Tahun,levels=c(98,99,0))})
>
>
> agg_dt1<-aggregate(x=dat2[,3],by=dat2[,c(1,2)],FUN=sum)
> head(agg_dt1)
> # Tahun Bahun x
> #1 98 1 1252
> #2 99 1 680
> #3 0 1 687
> #4 98 2 761
> #5 99 2 860
> #6 0 2 786
> I guess this is what you wanted.
>
>
> In addition, you can also use ddply() with a different way of grouping: but
> with the same result.
> library(plyr)
> dd_dt1<-ddply(dat2,.(Tahun,Bahun),summarize, sum(x))
> head(dd_dt1)
> # Tahun Bahun ..1
> #1 98 1 1252
> #2 98 2 761
> #3 98 3 440
> #4 98 4 597
> #5 98 5 987
> #6 98 6 692
> tail(dd_dt1)
> # Tahun Bahun ..1
> #31 0 7 685
> #32 0 8 504
> #33 0 9 633
> #34 0 10 553
> #35 0 11 914
> #36 0 12 1039
>
> A.K.
>
>
>
>
>
>
> ----- Original Message -----
> From: Roslina Zakaria <zrosl...@yahoo.com>
> To: "r-help@r-project.org" <r-help@r-project.org>
> Cc:
> Sent: Friday, October 5, 2012 8:09 PM
> Subject: [R] arrange data
>
> Dear r-users,
>
> I have dailly rainfall data from year 1971 to 2000. I use aggregate to form
> monthly rainfall data. What I don't understand is that the data for the year
> 2000 become on the top, instead of year 1971. Here are some codes and output:
>
>
> agg_dt1 <- aggregate(x=dt1[,4],by=dt1[,c(1,2)],FUN=sum)
>
>> head(agg_dt1,20); tail(agg_dt1,20)
> Tahun Bulan x
> 1 0 1 398.6
> 2 71 1 934.9
> 3 72 1 107.2
> 4 73 1 236.4
> 5 74 1 10.5
> 6 75 1 744.6
> 7 76 1 9.2
> 8 77 1 108.7
> 9 78 1 251.5
> 10 79 1 197.3
> 11 80 1 144.1
> 12 81 1 104.5
> 13 82 1 17.7
> 14 83 1 151.8
> ...
>
> Thank you so much for your help.
>
> Roslina
> [[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.
>
>
> ______________________________________________
> 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.
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