R help - Aug 2011 - How to get the date of specific value within a zoo object?

Hi all,

I have a zoo time series object, see below code:
-------------------------------------------------------------------------------------------

# This is a pasteable example
library(zoo)

x <- c(1, 2, 3, 4, 5)
dt <- c("2011-01-01", "2011-01-02",
"2011-01-03", "2011-01-04", "201-01-05")
ts <- zoo(x, ts)

-------------------------------------------------------------------------------------------

Now, I want to know the date when 'ts' equal to a specific value. In
this
example, suppose I want to know when the ts = 3? The program should return
"2011-01-03".

Is there a function to do this job conveniently?

Regards,
Richard

-----
Richard Ma
PhD student, Ecology & Remote Sensing
Climate Change Cluster, Department of Environment Science
University of Technology, Sydney
http://everydropr.wordpress.com
--
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I'd suggest you look into the xts class and write

require(xts)
xts = as.xts(1:5,Sys.Date()+1:5)
time(xts)[xts==3]

By the way, your code isn't pastable for me: not sure why.

Michael Weylandt

On Tue, Aug 9, 2011 at 10:39 PM, Richard Ma <xuanlong.ma@uts.edu.au>
wrote:
> Hi all,
>
> I have a zoo time series object, see below code:
>
>
-------------------------------------------------------------------------------------------
>
> # This is a pasteable example
> library(zoo)
>
> x <- c(1, 2, 3, 4, 5)
> dt <- c("2011-01-01", "2011-01-02",
"2011-01-03", "2011-01-04",
> "201-01-05")
> ts <- zoo(x, ts)
>
>
>
-------------------------------------------------------------------------------------------
>
> Now, I want to know the date when 'ts' equal to a specific value.
In this
> example, suppose I want to know when the ts = 3? The program should return
> "2011-01-03".
>
> Is there a function to do this job conveniently?
>
> Regards,
> Richard
>
> -----
> Richard Ma
> PhD student, Ecology & Remote Sensing
> Climate Change Cluster, Department of Environment Science
> University of Technology, Sydney
> http://everydropr.wordpress.com
> --
> View this message in context:
>
http://r.789695.n4.nabble.com/How-to-get-the-date-of-specific-value-within-a-zoo-object-tp3731885p3731885.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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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