[R] How can i keep only latest entries?

[p_connolly at slingshot.co.nz]

Quoting Mat <matthias.weber at fnt.de>:

> Hello togehter,
>
> i have a data.frame like this one:
>
>     No. Date                 last change
> 1  1     2012-10-04     change settings
> 2  1     2012-10-20     bug fix
> 3  1     2012-11-05     final
> 4  2     2013-01-15    new task
> 5  2     2013-01-16    Bug fix
> 6  2     2013-01-17    final
>

Calling your data frame, x and assuming the `last change` column is character,

x[x$`last change` == "final",]

will give what you want.  If `last change` is a factor column (likely),


x[as.character(x$`last change`) == "final",]


If you don't have spaces in your column names, you'd avoid using the 
backticks.

HTH



> now i want a new data.frame, who show me only the newest entries according
> to the No.
> The solution look like this one:
>
>    No. Date                last change
> 1  1     2012-11-05   final
> 2  2     2013-01-17   final
>
> can anyone help me?
>
> thanks.
>
> Mat
>
>
>
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