Hello, R-fellows,

I have a question that I really don't know how to solve. I have spent hours
on line surfing for possible solutions but in veil. Please if anyone could
help me handle this issue, you would be so appreciated!

I have a "grouped" dataset like this:

> data
  Study TX AEs   N
1     1     1    3       5
2     1     0    2       7
3     2     1    1      10
4     2     0    2       7
5     3     1    1       8
6     3     0    1       4

where Study is the study id, TX is treatment, AEs is how many people in
this trial is positive, and N is the number of the subjects. Therefore, for
the row 1, it stands for: It is the treatment arm for the study one, where
there are 5 subjects and 3 of them are positive. The row 2 stands for: It
is the control arm of the study 1 where there are 7 subjects and 2 of them
are positive.

Now I would like to "un-group them", make it like:

Study  TX   AEs
   1         1      1
   1         1      1
   1         1      1
   1         1      0
   1         1      0
   1         0      1
   1         0      1
   1         0      0
   1         0      0
   1         0      0
   1         0      0
   1         0      0
   2         1      1
   .....................
  .....................


But I wasn't able to do it. In fact I wrote a small function, and use
"lapply" to get what I want. It worked well, and did give me what I want.
But I wasn't able to collapse all the returns into one single data frame
for subsequent analysis.

The function I wrote:

subset = function(i){
d = c(rep(data[i,1], data[i,4]), rep(data[i,2], data[i,4]), rep(0:1,
c(data[i,4] - data[i,3],data[i,3])))
d = matrix(d, data[i,4],3)
d
}

then:

Data = lapply(1:6, subset)
Data

Therefore, I tried to write a loop. But no matter how I tried, I can't get
what I want.

Any idea?

Thank you so much!

Best,


-- 
Cheenghee Masaki Koh, MSW, MS(c), PhD Student
School of Social Service Administration
Department of Health Studies, Division of Biological Science
University of Chicago

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