Reputation: 3
I have a panel dataset with many variables. The three most relevant variables are: "cid" (country code), 'time" (0-65), and "event" (0, 1, 2, 3, 4, 5, 6).
I am trying to run a cox regression (using coxph
), however, since the time variable has different starting and ending points for each country, I need to first create a start time and end time variable. Here is where I run into my problem.
Here is what a sample of the three main variables may look like:
> data
cid time event
[1,] "AFG" "20" "0"
[2,] "AFG" "21" "0"
[3,] "AFG" "22" "0"
[4,] "AFG" "23" "0"
[5,] "AFG" "24" "0"
[6,] "AFG" "25" "0"
[7,] "AFG" "26" "1"
[8,] "AFG" "27" "1"
[9,] "AFG" "28" "1"
[10,] "AFG" "29" "1"
The idea is to convert this data into the following:
> data
cid time1 time2 event
[1,] "AFG" "20" "25" "0"
[2,] "AFG" "26" "29" "1"
How exactly does one go about doing this (keeping in mind that there are quite a few other explanatory variables in my dataset)?
Upvotes: 0
Views: 105
Reputation: 3833
subset1<- data[data$event==0,]
subset1
subset2<- data[data$event==1,]
subset2
s1<- cbind(cid="AFG",time1=min(subset1$time),time2=max(subset1$time),event = 0)
s1
s2<- cbind(cid="AFG",time1=min(subset2$time),time2=max(subset2$time),event = 1)
s2
data1=rbind(s1,s2)
data1
# cid time1 time2 event
# [1,] "AFG" "20" "25" "0"
# [2,] "AFG" "26" "29" "1"
Hope this would help a little.
Upvotes: 0
Reputation: 1102
You could use dplyr and pipe. This solution will work if your data is always ordered sequentially as in your example.
data<-data.frame(cid=rep("AFG",10),time=seq(20,29,1),event=c(0,0,0,0,0,0,1,1,1,1))
library(dplyr)
data %>% group_by(cid,event) %>%
summarise(time1=min(time),time2=max(time))
Upvotes: 1