R help - Sep 2010 - tail.matrix returns matrix, while tail.mts return vector

Hi

I have a few problems with tail/head when applied to multiple time 
series. I'm not sure as whether I did not understand the function or 
whether it correspond to an unexpected behavior.

When head(a,n) is applied on data.frame or matrix, it returns a 
data-frame or matrix with first n obs of *each* variable. When applied 
to a mts object, it returns first n obs of *first* variable only,  not 
of all... The same for tail(). See:

head(freeny)
###mts object
head(EuStockMarkets)
#is equivalent to:
head(EuStockMarkets[,1])

I guess it comes from absence of a head method for mts. Does it seem 
reasonable to have also a head.mts or did I misunderstand something?

Thanks

Hi Mat,
You might be able to use the matrix method to get what you want.

head.matrix(EuStockMarkets)

-Ista

On Sat, Sep 4, 2010 at 1:15 PM, mat <matthieu.stigler at gmail.com>
wrote:
> Hi
>
> I have a few problems with tail/head when applied to multiple time series.
> I'm not sure as whether I did not understand the function or whether it
> correspond to an unexpected behavior.
>
> When head(a,n) is applied on data.frame or matrix, it returns a data-frame
> or matrix with first n obs of *each* variable. When applied to a mts
object,
> it returns first n obs of *first* variable only, ?not of all... The same
for
> tail(). See:
>
> head(freeny)
> ###mts object
> head(EuStockMarkets)
> #is equivalent to:
> head(EuStockMarkets[,1])
>
> I guess it comes from absence of a head method for mts. Does it seem
> reasonable to have also a head.mts or did I misunderstand something?
>
> Thanks
>
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>


-- 
Ista Zahn
Graduate student
University of Rochester
Department of Clinical and Social Psychology
http://yourpsyche.org