[R] Reading time/date string
Prof Brian Ripley
ripley at stats.ox.ac.uk
Thu Aug 9 09:27:54 CEST 2007
On Thu, 9 Aug 2007, Matthew Walker wrote:
> Thanks Mark, that was very helpful. I'm now sooooo close!
> Can anyone tell me how to extract the "value" from an instance of a
> "difftime" class? I can see the value, but how can I place it in a
Hint: you want the number, not the value (which is a classed object).
> > time_string1 <- "10:17:07 02 Aug 2007"
> > time_string2 <- "13:17:40 02 Aug 2007"
> > time1 <- strptime(time_string1, format="%H:%M:%S %d %b %Y")
> > time2 <- strptime(time_string2, format="%H:%M:%S %d %b %Y")
> > time_delta <- difftime(time2,time1, unit="sec")
> > time_delta
> Time difference of 10833 secs # <--- I'd like this value just here!
> > data.frame(time1, time2, time_delta)
> Error in as.data.frame.default(x[[i]], optional = TRUE) :
> cannot coerce class "difftime" into a data.frame
> Thanks again,
> Mark W Kimpel wrote:
>> Look at some of these functions...
>> DateTimeClasses(base) Date-Time Classes
>> as.POSIXct(base) Date-time Conversion Functions
>> cut.POSIXt(base) Convert a Date or Date-Time Object to a Factor
>> format.Date(base) Date Conversion Functions to and from Character
>> Mark W. Kimpel MD ** Neuroinformatics ** Dept. of Psychiatry
>> Indiana University School of Medicine
>> 15032 Hunter Court, Westfield, IN 46074
>> (317) 490-5129 Work, & Mobile & VoiceMail
>> (317) 663-0513 Home (no voice mail please)
>> Matthew Walker wrote:
>>> Hello everyone,
>>> Can anyone tell me what function I should use to read time/date
>>> strings and turn them into a form such that I can easily calculate
>>> the difference of two? The strings I've got look like "10:17:07 02
>>> Aug 2007". If I could calculate the number of seconds between them
>>> I'd be very happy!
>>> R-help at stat.math.ethz.ch mailing list
>>> PLEASE do read the posting guide
>>> and provide commented, minimal, self-contained, reproducible code.
> R-help at stat.math.ethz.ch mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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