R help - Mar 2011 - xts POSIXct index format

Hi,

I cannot figure out how to change the index format when displaying POSIXct
objects.

Would like the xts index to display as %H:%M:%OS3 when doing viewing the xts
object.  

Think I am missing the obvious.

Cheers,
Chris

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On Mar 4, 2011, at 6:57 PM, rivercode wrote:
> Hi,
>
> I cannot figure out how to change the index format when displaying  
> POSIXct
> objects.
>
> Would like the xts index to display as %H:%M:%OS3 when doing viewing  
> the xts
> object.
If you are not satisfied with the default format, you have (at least)  
two options:
a) specify a format when you call print
b) redefine the default.

The default is determined within the  print.xts function by a call to  
indexFormat

 > indexFormat
function (x)
{
     attr(x, ".indexFORMAT")
}
<environment: namespace:xts>

So it looks as though you would need to either replace indexFormat or  
change the attribute of your xts objects. Read further at:

?indexFormat
>
> Think I am missing the obvious.
If you mean looking at the source code, then perhaps you were missing  
the obvious, or at least merely readily accessible. I don't actually  
see the option of including a format string in the attribute, so  
modifying the function may be needed.

-- 
David Winsemius, MD
Heritage Laboratories
West Hartford, CT

Hi Chris,

Perhaps something like this?

require(xts)
ds <- options(digits.secs=6) # so we can see sub-seconds
x <- xts(1:10, as.POSIXct("2011-01-21") + c(1,1,1,2:8)/1e3)
x
indexFormat(x) <- "%H:%M:%OS3"
x

Hope that helps,
--
Joshua Ulrich ?| ?FOSS Trading: www.fosstrading.com



On Fri, Mar 4, 2011 at 5:57 PM, rivercode <aquanyc at gmail.com>
wrote:
> Hi,
>
> I cannot figure out how to change the index format when displaying POSIXct
> objects.
>
> Would like the xts index to display as %H:%M:%OS3 when doing viewing the
xts
> object.
>
> Think I am missing the obvious.
>
> Cheers,
> Chris
>
> --
> View this message in context:
http://r.789695.n4.nabble.com/xts-POSIXct-index-format-tp3336136p3336136.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
>

Thank you for your help.

indexFormat(x) solved the problem nicely.
> head(a)
2011-03-04 09:30:00.0 22.10
2011-03-04 09:30:00.1 22.09
2011-03-04 09:30:00.2 22.10
2011-03-04 09:30:00.3 22.09
2011-03-04 09:30:00.4 22.10
2011-03-04 09:30:00.5 22.09
> indexFormat(a) <- "%H:%M:%OS3"
> head(a)
              
09:30:00.000 22.10
09:30:00.100 22.09
09:30:00.200 22.10
09:30:00.300 22.09
09:30:00.400 22.10
09:30:00.500 22.09

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On Mar 5, 2011, at 11:28 AM, Joshua Ulrich wrote:
> Hi Chris,
>
> Perhaps something like this?
>
> require(xts)
> ds <- options(digits.secs=6) # so we can see sub-seconds
> x <- xts(1:10, as.POSIXct("2011-01-21") + c(1,1,1,2:8)/1e3)
> x
> indexFormat(x) <- "%H:%M:%OS3"
> x
>
Joshua;

Does your reading of help(indexFormat) lead you to that suggestion?  
When I read it I thought that indexFormat would only accept onoe of "  
Date, POSIXct, chron,yearmon, yearqtr or timeDate." Those were the  
formats mentioned in the immediately preceding paragraph. I went to  
the help page hoping I would be told I could use format strings but  
left it thinking that I could only specify format classes.

-- 
David

> Hope that helps,
> --
> Joshua Ulrich  |  FOSS Trading: www.fosstrading.com
>
>
>
> On Fri, Mar 4, 2011 at 5:57 PM, rivercode <aquanyc at gmail.com>
wrote:
>> Hi,
>>
>> I cannot figure out how to change the index format when displaying  
>> POSIXct
>> objects.
>>
>> Would like the xts index to display as %H:%M:%OS3 when doing  
>> viewing the xts
>> object.
>>
>> Think I am missing the obvious.
>>
>> Cheers,
>> Chris
>>
>> --
>> View this message in context:
http://r.789695.n4.nabble.com/xts-POSIXct-index-format-tp3336136p3336136.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> 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.
>>
>
> ______________________________________________
> 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.
David Winsemius, MD
Heritage Laboratories
West Hartford, CT