R help - Aug 2010 - data frame handling

Dear all, 

I have an xts object , t.xts with 4 columns: "v1" "DD1"
"v2" "DD2" and
created a data frame :

t <- as.data.frame(t.xts)

I would like to extract data and create a new data frame for when the values
in column DD1 falls between 0 and 30 and extract the corresponding v1 value.

How can I do this?

Thanks.



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On Aug 16, 2010, at 5:53 AM, Lily_stats wrote:
>
> Dear all,
>
> I have an xts object , t.xts with 4 columns: "v1" "DD1"
"v2" "DD2" and
> created a data frame :
>
> t <- as.data.frame(t.xts)
"t" is not the best choice of names for an object because it is the  
name of a commonly used function

Let's instead assume you used "tt". Try:

tt[which(tt$DD1 >0 & tt$DD1 < 30), "v1"]

Or:

subset(tt, subset=which(tt$DD1 >0 & tt$DD1 < 30),
select="v1")
>
> I would like to extract data and create a new data frame for when  
> the values
> in column DD1 falls between 0 and 30 and extract the corresponding  
> v1 value.
>
> How can I do this?
>
> Thanks.
>
David Winsemius, MD
West Hartford, CT