[R] missing date and time intervals in data frame

[David Winsemius]

On Mar 4, 2010, at 4:45 PM, Kindra Martinenko wrote:

> I posted a similar question, but feel it needs a bit more elaboration.
>
> I have a data frame (read from a csv file) that may have missing  
> rows.  Each
> day has 7 time intervals associated with it, with a range from 17:00  
> hrs to
> 18:00 hrs in 10 minute bins.
>
> What I am looking for is a script that will run through the data  
> frame and
> insert "NA"in the Volume column for any dates that are missing a time
> interval.  For example:
>
>          Date            Time             Camera
> Volume
> 57  2009-10-09 5:00:00 PM MANBRIN_RIVER_NB    210
> 58  2009-10-09 5:10:00 PM MANBRIN_RIVER_NB    207
> 59  2009-10-09 5:20:00 PM MANBRIN_RIVER_NB    250
> 60  2009-10-09 5:30:00 PM MANBRIN_RIVER_NB    193
> 61  2009-10-09 5:40:00 PM MANBRIN_RIVER_NB    205
> 62  2009-10-09 6:00:00 PM MANBRIN_RIVER_NB    185

Here is one method of generating a series of time points at 10 minute  
intervals:

 > as.POSIXlt("5:00:00 PM", format="%I:%M:%s %p" ) + (1:20)*60*10
  [1] "2010-03-04 05:10:00 EST" "2010-03-04 05:20:00 EST" "2010-03-04  
05:30:00 EST"
  [4] "2010-03-04 05:40:00 EST" "2010-03-04 05:50:00 EST" "2010-03-04  
06:00:00 EST"
  [7] "2010-03-04 06:10:00 EST" "2010-03-04 06:20:00 EST" "2010-03-04  
06:30:00 EST"
[10] "2010-03-04 06:40:00 EST" "2010-03-04 06:50:00 EST" "2010-03-04  
07:00:00 EST"
[13] "2010-03-04 07:10:00 EST" "2010-03-04 07:20:00 EST" "2010-03-04  
07:30:00 EST"
[16] "2010-03-04 07:40:00 EST" "2010-03-04 07:50:00 EST" "2010-03-04  
08:00:00 EST"
[19] "2010-03-04 08:10:00 EST" "2010-03-04 08:20:00 EST"

Applying that to the solution you referenced should finish the job.

-- 
David.
>
> Note that between row 61 and row 62, there is a missing time  
> interval (5:50
> PM).  I want the data frame to look like this:
>
>     Date                 Time           Camera
> Volume
> 57  2009-10-09 5:00:00 PM MANBRIN_RIVER_NB    210
> 58  2009-10-09 5:10:00 PM MANBRIN_RIVER_NB    207
> 59  2009-10-09 5:20:00 PM MANBRIN_RIVER_NB    250
> 60  2009-10-09 5:30:00 PM MANBRIN_RIVER_NB    193
> 61  2009-10-09 5:40:00 PM MANBRIN_RIVER_NB    205
> *62  2009-10-09 5:50:00 PM MANBRIN_RIVER_NB  NA*
> 62  2009-10-09 6:00:00 PM MANBRIN_RIVER_NB    185
>
>
> Thanks in advance,
> Kindra
>
> 	[[alternative HTML version deleted]]
>
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT