[R] duplicate values

[jim holtman]

This should do it for you:

> x <- read.table(textConnection(         "Date time                      Temperature
+ 1        2008-6-1 00:00:00      5
+ 2        2008-6-1 02:00:00      5
+ 3        2008-6-1 03:00:00      6
+ 4        2008-6-1 03:00:00      0
+ 5        2008-6-1 04:00:00      6
+ 6        2008-6-1 04:00:00      0
+ 7        2008-6-1 05:00:00      7
+ 8        2008-6-1 06:00:00      7"), header=TRUE)
> closeAllConnections()
> # create datetime
> x$dt <- as.POSIXct(paste(x$Date, x$time))
> # create list of duplicate values next to each other
> dup <- c(FALSE, diff(x$dt) == 0)
> # remove
> x[!dup,]
      Date     time Temperature                  dt
1 2008-6-1 00:00:00           5 2008-06-01 00:00:00
2 2008-6-1 02:00:00           5 2008-06-01 02:00:00
3 2008-6-1 03:00:00           6 2008-06-01 03:00:00
5 2008-6-1 04:00:00           6 2008-06-01 04:00:00
7 2008-6-1 05:00:00           7 2008-06-01 05:00:00
8 2008-6-1 06:00:00           7 2008-06-01 06:00:00


On Sun, Nov 16, 2008 at 1:10 PM, Antje Nöthlich <antno at web.de> wrote:
> Hei R Users,
>
> i have the following dataframe:
>
>          Datetime                      Temperature             and many more collumns
> 1        2008-6-1 00:00:00      5
> 2        2008-6-1 02:00:00      5
> 3        2008-6-1 03:00:00      6
> 4        2008-6-1 03:00:00      0
> 5        2008-6-1 04:00:00      6
> 6        2008-6-1 04:00:00      0
> 7        2008-6-1 05:00:00      7
> 8        2008-6-1 06:00:00      7
> .            .                                .
> .            .                                .
> .            .                                .
> 3000  2008-8-31 00:00:00    3
>
>
> the problem is that row 3 & 4 and row 5 & 6 have the same "Datetime" value but they differ in the values of the "Temperature" column.
> Now for the whole dataframe i would like to delete rows that have the same "Datetime" value as the prior row.
> I have tried unique(dataframe), but it does not work here because the rows are no real duplicates of each other.
> thanks in advance for your help!
>
> Antje
>
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>



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

What is the problem that you are trying to solve?