The warning message does tell you exactly what was wrong. You are
trying to merge zoo objects that have two different index classes.
The first is "POSIXct" and the second is "Date" class. Next
time
please provide your data in reproducible form
as shown here:
> library(zoo)
> z1 <- zoo(1:6, as.Date(c("1950-01-05", "1950-01-06",
"1950-01-09",
+ "1950-01-10", "1950-01-11",
"1950-01-12")))> z2 <- zoo(c(16.66, 16.85, 16.93, 16.98, 17.08, 17.03),
+ as.POSIXct(c("1950-01-03, GMT", "1950-01-04, GMT",
"1950-01-05, GMT",
+ "1950-01-06, GMT", "1950-01-09 GMT", "1950-01-10
GMT")))>
> merge(z1, z2 = aggregate(z2, as.Date, identity))
z1 z2
1950-01-03 NA 16.66
1950-01-04 NA 16.85
1950-01-05 1 16.93
1950-01-06 2 16.98
1950-01-09 3 17.08
1950-01-10 4 17.03
1950-01-11 5 NA
1950-01-12 6 NA>
>
> # or
> z2.Date <- z2
> time(z2.Date) <- as.Date(time(z2.Date))
>
> merge(z1, z2.Date)
z1 z2.Date
1950-01-03 NA 16.66
1950-01-04 NA 16.85
1950-01-05 1 16.93
1950-01-06 2 16.98
1950-01-09 3 17.08
1950-01-10 4 17.03
1950-01-11 5 NA
1950-01-12 6 NA
On Thu, May 20, 2010 at 10:48 AM, Research <risk2009 at ath.forthnet.gr>
wrote:> Hello,
>
> I have a zoo time series object (say a) ?with the following time
> stamp/format
>
>
>
> [1] "1950-01-03 GMT" "1950-01-04 GMT" "1950-01-05
GMT" "1950-01-06 GMT"
> [5] "1950-01-09 GMT" "1950-01-10 GMT"
>
>
> and another (say b) with
>
>
> [1] "1950-01-05" "1950-01-06" "1950-01-09"
"1950-01-10" "1950-01-11"
> [6] "1950-01-12"
>
>
> I want to merge these series ? but when I try:
>
>
>> head(merge(a, b ))
> ? ? ? ? ? ? ? ? ? ?a ? ? ? ? ? ? ? ? ? b
> 1950-01-03 02:00:00 ? ? ? 16.66 ? NA
> 1950-01-04 02:00:00 ? ? ? 16.85 ? NA
> 1950-01-05 02:00:00 ? ? ? 16.93 ? NA
> 1950-01-06 02:00:00 ? ? ? 16.98 ? NA
> 1950-01-09 02:00:00 ? ? ? 17.08 ? NA
> 1950-01-10 02:00:00 ? ? ? 17.03 ? NA
> Warning message:
> In merge.zoo(a, b) :
> ?Index vectors are of different classes: POSIXt Date
>>
>
> Anybody can help? ?I tried as.POSIXct(a,tz="GMT") but it
doesn't seem to
> work....
>
> Many thanks in advance!
>
> Costas
> ? ? ? ? ? ? ?_
> platform ? ? ? i386-pc-mingw32
> arch ? ? ? ? ? i386
> os ? ? ? ? ? ? mingw32
> system ? ? ? ? i386, mingw32
> status
> major ? ? ? ? ?2
> minor ? ? ? ? ?10.1
> year ? ? ? ? ? 2009
> month ? ? ? ? ?12
> day ? ? ? ? ? ?14
> svn rev ? ? ? ?50720
> language ? ? ? R
> version.string R version 2.10.1 (2009-12-14)
>>
>
> ______________________________________________
> 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.
>