who can give me some hint?

Thanks a lot for your reply.

I expect a more flexible solution. Because I couldn't check that column one
by one.

If another Rep colum is:
useractivity_act
2
2
3
3
3
4
5
5
6
useractivity_idle
i should be able to write a program to make it as:
useractivity_act
2
3
4
5
6
useractivity_idle

Only keep 1st value of repeated values.
I have been working no it for a while....Still didnt get solution.
Thanks for your concentration.

Tammy

Date: Thu, 12 Mar 2009 08:03:11 -0400
Subject: Re: [R] who can give me some hint?
From: ggrothendieck at gmail.com
To: metal_licaling at live.com
CC: r-help at r-project.org

I assume the problem is to only keep those rows whose
Rep value is not equal to the Rep value in the prior row.
In that case just compare c("", Rep[-nr]) to Rep and
use the resulting vector, ix, to select out rows.
Rep <- as.character(act_2$Rep) could
be simplified to Rep <- act_2$Rep if Rep
is already known to be "character".


Lines <- "Date Dtime Hour Min Second Rep
51 2006-02-22 14:52:18 14 52 18 useractivity_act
52 2006-02-22 14:52:18 14 52 18 4
55 2006-02-22 14:52:49 14 52 49 4
57 2006-02-22 14:52:51 14 52 51 4
58 2006-02-22 14:52:52 14 52 52 3
60 2006-02-22 14:54:42 14 54 42 useractivity_idle"

act_2 <- read.table(textConnection(Lines), header = TRUE, as.is = TRUE)

nr <- nrow(act_2)
Rep <- as.character(act_2$Rep)
ix <- Rep != c("", Rep[-nr])
act_2[ix]

On Thu, Mar 12, 2009 at 6:25 AM, Tammy Ma <metal_licaling at live.com> wrote:

?Hi All,

act_2

? ? ? ? Date ? ?Dtime Hour Min Second ? ? ? ? ? ? ? Rep
51 2006-02-22 14:52:18 ? 14 ?52 ? ? 18 ?useractivity_act
52 2006-02-22 14:52:18 ? 14 ?52 ? ? 18 ? ? ? ? ? ? ? ? 4
55 2006-02-22 14:52:49 ? 14 ?52 ? ? 49 ? ? ? ? ? ? ? ? 4
57 2006-02-22 14:52:51 ? 14 ?52 ? ? 51 ? ? ? ? ? ? ? ? 4
58 2006-02-22 14:52:52 ? 14 ?52 ? ? 52 ? ? ? ? ? ? ? ? 3
60 2006-02-22 14:54:42 ? 14 ?54 ? ? 42 useractivity_idle

I want to change act_2 to
? ? ? ? Date ? ?Dtime Hour Min Second ? ? ? ? ? ? ? Rep

51 2006-02-22 14:52:18 ? 14 ?52 ? ? 18 ?useractivity_act

52 2006-02-22 14:52:18 ? 14 ?52 ? ? 18 ? ? ? ? ? ? ? ? 4
58 2006-02-22 14:52:52 ? 14 ?52 ? ? 52 ? ? ? ? ? ? ? ? 3
60 2006-02-22 14:54:42 ? 14 ?54 ? ? 42 useractivity_idle

in other word, I want to keep 1st if there are many repeated value, I
made the program as:


rm_r<-function(act_2){
?dm<-dim(act_2)[1]-1
?for(i in 2:dm){

?if(act_2$Rep[i+1]==act_2$Rep[i]){
? act_2<-act_2[-(i+1),]
? }else{
? act_2<-act_2
? }
?}
return(act_2)
}

when it moved one row on 1st loop, i should still start 2 but it become
3 at 2nd loop, if I add i<-i-1, then i go to 1
seems not reasonbale. How should I modify it`?

Tammy