This does exactly what is needed.

Thanks guys!

 

-----Original Message-----
From: markleeds@verizon.net [mailto:markleeds@verizon.net] 
Sent: Thursday, June 18, 2009 5:30 PM
To: rene.schoenemann@tu-berlin.de
Subject: Re: [R] filtering number of values in a data frame

 


do.call(rbind,lapply(unname(split(DF,list(DF$X1,DF$START),drop=TRUE)),
function(.df) {
    data.frame(.df[1,1:4],count=nrow(.df))
}))





On Jun 18, 2009, René Schönemann <rene.schoenemann@tu-berlin.de> wrote: 

Dear list,

given is the following data frame df():

Number Place Start End
1 218024740787 HHO 5 263 2008-01-02 00:21:14 2008-01-03 15:25:16
2 218024740787 HHO 5 263 2008-01-02 00:21:14 2008-01-02 00:21:14
3 318039091794 HHO 5 263 2008-01-02 00:21:14 2008-01-02 13:22:54
4 318039091794 HHO 5 263 2008-01-02 00:21:14 2008-01-02 00:21:14
5 318039379900 HHO 1 104 2008-01-02 06:45:01 2008-01-02 09:15:23

Now, I want to count the number of equal values of column "Start" but I also
want the other columns to be preserved.

Using:

rle(as.character(df$Start)) -> m
n <- data.frame(m$values, m$lengths)

produces a list of items according to their frequency of the Start point:

m.values m.lengths
1 2008-01-02 00:21:14 4
2 2008-01-02 06:45:01 1


I want now also other columns to be in this new data frame. It should look
like that:

Number Place m.values m.lengths
1 218024740787 HHO 5 263 2008-01-02 00:21:14 4
2 318039379900 HHO 1 104 2008-01-02 06:45:01 1


Does anybody can help me with this?

Thanking you in advance!

René Schönemann

-- 
______________________________________________________

Technische Universität Berlin
Institut für Land- und Seeverkehr
Fachgebiet Schienenfahrwege und Bahnbetrieb 
Prof. Dr.-Ing. habil. Jürgen Siegmann

Post Sekretariat SG 18
Salzufer 17-19
D-10587 Berlin

Telefon +49 (0)30 314 - 23 314 

Internet http://www.railways.tu-berlin.de
______________________________________________________

Dipl.-Verk.wirtsch. René Schönemann
- Wissenschaftlicher Mitarbeiter -

Telefon +49 (0)30 314 - 22 710
Telefax +49 (0)30 314 - 25 530

E-Mail RSchoenemann@railways.tu-berlin.de
______________________________________________________

Technische Universität Berlin
Körperschaft öffentlichen Rechts

Präsident Prof. Dr. Kurt Kutzler 

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


	[[alternative HTML version deleted]]


