[R] duplicate values

[Erik Iverson]

Antje -

I may be missing something, but I usually do this with the negation of 
duplicated instead of unique.

So, as an example:

test <- data.frame(a = rep(1:5, each = 2),
    b = rep(1:5, each = 2), c = rnorm(10))

test[!duplicated(test[c("a", "b")]), ]

Hope that helps!

Erik

Antje Nöthlich 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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