Hi all,
I have a data set that contains samples collected over time. In
each time period the total number of samples are given (X2) The goal
is to select 500 random samples. The selection should be based on
time (select time periods until I reach 500 samples). Also the time
period should have greater than 0 for X1 variable. X1 is an indicator
variable.
Select "time" until reaching the sum of X2 is > 500 and if X1 is > 0
tab <- read.table(textConnection(" time X1 X2
1 0 251
2 5 230
3 1 300
4 0 25
5 2 10
6 3 101
7 1 300
8 4 185 "),header = TRUE)
In the above example, samples from time 1 and 4 will not be selected
( X1 is zero)
So I could reach my target by selecting time 6,7, and 8 or time 2 and
3 and so on.
Can any one help to do that?
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