I'm having trouble creating a looping variable and i can't see wher ethe
problem arises from any hep gratfully appreciated

First create a table

x<-table(SURVEY$n_0,exposed)
> x
          exposed
           False True
  Under 16    24    1
  16-19       68    9
  20-24      190   37
  25-34      555  204
  35-44      330   87
  45-54      198   65
  55-64       67   35
  65+         10    8

Now ectors to store counts and column proportions

> xT<-x[,"True"]
> xF<-x[,"False"]
> yT<-x[,"True"]/colSums(x)
> yF<-x[,"False"]/colSums(x)

check length for dynamic looping
> length(yT)
[1] 8

now create loop
> for(i in 1:length(yT)){
+ pwr.2p2n.test(2*(asin(sqrt(yT[i]))-asin(sqrt(yF[i]))),n1=xT[i],n2=xF[i])
+ }
Error in pwr.2p2n.test(2 * (asin(sqrt(yT[i])) - asin(sqrt(yF[i]))), n1 =
xT[i],  :
  number of observations in the first group must be at least 2

this confuses me as if i enter the data as values the procedure works?

Thanks in advance

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