[R] store result of loop in df

[Ivan Calandra]

Dear Alain,

The problem is that you save the results of each iteration in df$VAR. So 
obviously, you overwrite df$VAR at each iteration.

What you need to do it to create an empty vector that contains the right 
number of elements and then iteratively fill this list. You can then 
combine df and that vector

That would do it:
results <- vector(mode="numeric", length=nrow(df))
for (i in seq_along(results)){
     results[i] <- binom.test(df[i,1],df[i,2],0.065)$estimate[[1]]

}
df$VAR1 <- results

You could also use apply():
foo <- function(x) binom.test(x[[1]],x[[2]],0.065)$estimate
df$VAR2 <- apply(df[,1:2], 1, FUN=foo)

identical(df$VAR1, df$VAR2)

HTH,
Ivan

--
Ivan Calandra, PhD
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Le 29/07/2016 à 10:52, Alain D. via R-help a écrit :
> Dear list,
>
> I have a dataframe df:
>
> df<-data.frame(x=c(5,32,18,3,17), n=c(11,200,432,20,60))
>
> Now I want to run n=nrow binom.test() with x being the number of success and n
> the number of trials and then store the results as a new VAR in df.
>
> I tried
>
>    for (i in 1:nrow(df)){
>    df$VAR<-(binom.test(df[i,1],df[i,2],0.065))$estimate[[1]]
> }
>
> but bin does only contain the last result.
>
> What is wrong with my code? Can anyone help?
>
> Thank you in advance.
>
> Alain
>
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