[R] leap years in temporal series command ts

[Peter Zorglub]

Ok thanks. I got now a temporal series of 2557 elements thanks to the 
below code:

 > seriezoo=zooreg(serie, start=as.Date("2002-01-01"))
 > seriezooTS=as.ts(seriezoo)

The structure of seriezooTS is then the following one (str command):

 > str(seriezooTS)
               Time-Series [1:2557] from 11688 to 14244: 0.03424657 
0.03881249 0.03078472 0.03536114 ...

When applying the "decompose" command to get a seasonal decomposition, I 
got the following message:

 > decompose(seriezooTS, "mult")
               Error in decompose(seriezooTS, "mult") :
               time series has no or less than 2 periods

So, I think I have to transform the first and last days of the temporal 
series in terms of Date or some kind of POSIXct number. Am I wrong? And 
how can I do that?


Thanks in advance,




Peter

On 02/16/2011 04:21 PM, Gabor Grothendieck wrote:
> On Wed, Feb 16, 2011 at 6:51 AM, Peter Zorglub<peter.zorglub at gmail.com>  wrote:
>> Hi R community!
>>
>> I'd like to create a temporal series with ts command for the interval 1st
>> January 2002 - 31 December 2008. I have daily values, so this is a 2557 days
>> temporal series. I'm using this command :
>>
>>     ts(observations, start=2002, end=2009, freq=365)
>>
>> However, I don't get the correct temporal series since both frequency (365
>> OR 366 for leap years) and deltat (1/365 OR 1/366) are varying with the year
>> considered.
>>
>> So, is there a specific way to deal with leap years in the ts command or
>> have I to use another package?
> You could do this with an implied frequency of 1
>
> tt<- ts(1:10, start=as.Date("2000-01-01"))
>
> which would represent the times as days since the Epoch. You can
> recover the Date class dates with:
>
> as.Date(tt, origin = "1970-01-01")
>
> You might be better off using zoo or xts. e.g.
>
> library(zoo)
> z<- zooreg(1:10, start = as.Date("2000-01-01"))
>
> Its also possible to move back and forth:
>
> as.ts(z)
> as.zoo(tt)
> aggregate(as.zoo(tt), identity, as.Date)
>
>
>