[R] Count continuous dates

Joshua Wiley jwiley.psych at gmail.com
Thu Nov 11 07:45:15 CET 2010


Hi Tim,

Thanks for providing nice sample data!  It made this super easy :)

## use diff() to find the differences
## use rle() to find the run lengths
## use max to find the highest one
max(rle(as.vector(diff(x)))$lengths)


Cheers,

Josh

On Wed, Nov 10, 2010 at 10:07 PM, Tim Clark <mudiver1200 at yahoo.com> wrote:
> Dear List,
>
> I have a series of dates and I am needing to know the greatest length of
> continuous dates - i.e. the number of dates before a break in the series.  For
> example, below there are three continuous series of dates with lengths 4, 6, and
> 8.  How can I count the number of continuous dates?  rle() will do it for
> constant integers, but I can't figure a way to modify it for continuous dates.
>
> x<-c("1/10/10","2/10/10","3/10/10","4/10/10",
>      "6/10/10","7/10/10","8/10/10","9/10/10","10/10/10","11/10/10",
>
> "13/10/10","14/10/10","15/10/10","16/10/10","17/10/10","18/10/10","19/10/10","20/10/10")
>
> x<-strptime(x,"%d/%m/%y")
>
>
>
> Thanks!
>
> Tim
>  Tim Clark
> Marine Ecologist
> National Park of American Samoa
> Pago Pago, AS 96799
>
>
>
>
> ______________________________________________
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> 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
University of California, Los Angeles
http://www.joshuawiley.com/



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