[R] Contional

[jim holtman]

Is this what you want:  TRUE marks the ones to be removed

> mark <- (head(x$timestamp, -1) == tail(x$timestamp, -1)) &
+     (head(x$user_id, -1) == tail(x$user_id, -1))
> x$flag <- c(FALSE, mark)
> x
      Source_type           timestamp      user_id  flag
75381           0 07-07-2008-21:03:55 848307909687 FALSE
75379           1 07-07-2008-19:52:55 848307838407 FALSE
75380           2 07-07-2008-19:54:14 848307838407 FALSE
75378           1 07-07-2008-15:24:01 848285633277 FALSE
75374           1 07-07-2008-13:39:17 848273633667 FALSE
75377           2 07-07-2008-13:39:55 848273633667 FALSE
75376           2 07-07-2008-13:39:55 848273633667  TRUE
75375           2 07-07-2008-13:56:05 848273633667 FALSE
75373           1 07-07-2008-17:11:00 848272661427 FALSE
75371           1 07-07-2008-13:19:00 848270431847 FALSE
75372           2 07-07-2008-13:19:14 848270431847 FALSE
75369           1 07-07-2008-12:49:16 848269676907 FALSE
75370           2 07-07-2008-12:49:16 848269676907  TRUE
75366           1 07-07-2008-13:29:15 848263484847 FALSE
75368           2 07-07-2008-13:29:44 848263484847 FALSE
>




On Tue, Sep 23, 2008 at 4:44 PM, Michael Pearmain <mpearmain at google.com> wrote:
> Hi All,
>
> I'm having trouble selecting rows to delete, that i can't seem to overcome.
>
> Below is some sample data, i am trying to dedup the data based on each user,
> and simultaneously the timestamp (at the side i have highlighted expected
> row to be removed)
>
> I've looked at the lag function but can't seem to make it work?
>
> My logic ran along the lines of an ifelse statement and then remove after
> that, but it doesn't seem to work? Any help appreciated
>
> Let's call the data test
>
> test$lag <- ifelse(test$user_id==lag(test$user_id)
> & test$timestamp==lag(test$timestamp),1,0)
>
> Can anyone help on this?
>
> Mike
>
>
>
> Source_type           timestamp            user_id
> 75381           0 07-07-2008-21:03:55 848307909687
> 75379           1 07-07-2008-19:52:55 848307838407
> 75380           2 07-07-2008-19:54:14 848307838407
> 75378           1 07-07-2008-15:24:01 848285633277
> 75374           1 07-07-2008-13:39:17 848273633667
> 75377           2 07-07-2008-13:39:55 848273633667
> 75376           2 07-07-2008-13:39:55 848273633667    Remove
> 75375           2 07-07-2008-13:56:05 848273633667
> 75373           1 07-07-2008-17:11:00 848272661427
> 75371           1 07-07-2008-13:19:00 848270431847
> 75372           2 07-07-2008-13:19:14 848270431847
> 75369           1 07-07-2008-12:49:16 848269676907   Remove
> 75370           2 07-07-2008-12:49:16 848269676907
> 75366           1 07-07-2008-13:29:15 848263484847
> 75368           2 07-07-2008-13:29:44 848263484847
>
> Thanks in advance
>
>        [[alternative HTML version deleted]]
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?