[R] Raw epoch time from XTS

[Noah Silverman]

Josh,

Good point about including an example.

calling xcoredata() does work, but only for a *single* row of the data at a time.  In R, I'm used to passing an entire data structure or vector to a function and automatically getting back a vector of all the results.  In this case, it doesn't work that way.

The attr() function is probably the best solution.

Thanks!

--
Noah Silverman
UCLA Department of Statistics
8117 Math Sciences Building
Los Angeles, CA 90095

On Aug 20, 2011, at 1:03 AM, Joshua Wiley wrote:

> Hi Noah,
> 
> This is one of those cases where following the posting guide
> (particularly the minimal, reproducible example part) would have
> really helped.  Are you saying that calling:
> xcoredata(your_xts_object) does not give you the internal
> representation of time that you want?
> 
> data(sample_matrix)
> sample.xts <- as.xts(sample_matrix, descr='my new xts object')
> # returns a list, the index is the numeric representation of time
> displayed in the rows
> xcoredata(sample.xts)
> 
> You could also try the more direct:
> 
> attr(xts_object, "index")
> 
> If this is not what you want or is not working for you, providing us
> the output of dput() from the first few rows of your dataset and an
> example of what you do want would be spectacular.
> 
> Cheers,
> 
> Josh
> 
> On Sat, Aug 20, 2011 at 12:44 AM, Noah Silverman <noahsilverman at ucla.edu> wrote:
>> Hi,
>> 
>> I have a very large data set stored as an xts object.
>> 
>> xts is very nice about showing row labels as "human readable" dates and times.
>> 
>> I want the actual epoch values that are stored internally.  The only way I can find to access them is one-at-a-time using the internal function: xcoredata()
>> 
>> Calling this in an entire column, the "R" way doesn't work.  It will only return a single value.  Calling it in a loop for each row works but is painfully slow.
>> 
>> Since the epoch is stored internally, there must be some way to just grab it as a vector.  Does anyone know how?
>> 
>> Thanks!
>> 
>> --
>> Noah Silverman
>> UCLA Department of Statistics
>> 8117 Math Sciences Building
>> Los Angeles, CA 90095
>> 
>> ______________________________________________
>> 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.
>> 
> 
> 
> 
> -- 
> Joshua Wiley
> Ph.D. Student, Health Psychology
> Programmer Analyst II, ATS Statistical Consulting Group
> University of California, Los Angeles
> https://joshuawiley.com/