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
> On 29 Jul 2016, at 10:52, Alain D. via R-help <r-help at r-project.org> wrote: > > 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? >How about for (i in 1:nrow(df)){ df$VAR[i] <- (binom.test(df[i,1],df[i,2],0.065))$estimate[[1]] } Berend Hasselman
Hi Alain,
You are probably storing the result, replicated five times, in df$VAR.
Each cycle of the loop replaces the last value with the current value.
If you really want the entire output of binom.test in the last column:
multi.binom.test<-function(xs,ns) {
reslist<-list()
for(i in 1:length(xs)) reslist[[i]]<-binom.test(xs[i],ns[i])
return(reslist)
}
df$VAR<-multi.binom.test(df$x,df$n)
I suspect that you probably want only the p.value element.
Jim
On Fri, Jul 29, 2016 at 6:52 PM, Alain D. via R-help
<r-help at r-project.org> wrote:> 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
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
On 29/07/16 20:52, Alain D. via R-help wrote:> 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?Try: for (i in 1:nrow(df)){ df$VAR[i] <- binom.test(df[i,1],df[i,2],0.065)$estimate[[1]] } (Actually I was amazed that this works without initializing df$VAR, but it *does* work! There is no limit to the wondrous nature of R!) BTW -- calling your data frame "df" is a bad idea. There is a built-in function named "df", and on occasion the result of naming some other object "df" can be mysterious errors accompanied by opaque error messages. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
Dear Alain,
The problem is that you save the results of each iteration in df$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$VAR2)
HTH,
Ivan
--
Ivan Calandra, PhD
Scientific Mediator
University of Reims Champagne-Ardenne
GEGENAA - EA 3795
CREA - 2 esplanade Roland Garros
51100 Reims, France
+33(0)3 26 77 36 89
ivan.calandra at univ-reims.fr
--
https://www.researchgate.net/profile/Ivan_Calandra
https://publons.com/author/705639/
Le 29/07/2016 ? 10:52, Alain D. via R-help a ?crit :> Dear list,
>
> I have a dataframe df:
>
> df<-data.frame(x=c(5,32,18,3,17), n=c(11,200,432,20,60))
>
> Now I want to run n=nrow binom.test() with x being the number of success
and n
> the number of trials and then store the results as a new VAR in df.
>
> I tried
>
> for (i in 1:nrow(df)){
> df$VAR<-(binom.test(df[i,1],df[i,2],0.065))$estimate[[1]]
> }
>
> but bin does only contain the last result.
>
> What is wrong with my code? Can anyone help?
>
> Thank you in advance.
>
> Alain
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
Le 29/07/2016 ? 11:20, Rolf Turner a ?crit :> On 29/07/16 20:52, Alain D. via R-help wrote: >> Dear list, >> >> I have a dataframe df: >> >> df<-data.frame(x=c(5,32,18,3,17), n=c(11,200,432,20,60)) >> >> Now I want to run n=nrow binom.test() with x being the number of >> success and n >> the number of trials and then store the results as a new VAR in df. >> >> I tried >> >> for (i in 1:nrow(df)){ >> df$VAR<-(binom.test(df[i,1],df[i,2],0.065))$estimate[[1]] >> } >> >> but bin does only contain the last result. >> >> What is wrong with my code? Can anyone help? > > Try: > > for (i in 1:nrow(df)){ > df$VAR[i] <- binom.test(df[i,1],df[i,2],0.065)$estimate[[1]] > } > > (Actually I was amazed that this works without initializing df$VAR, > but it *does* work! There is no limit to the wondrous nature of R!)I was so sure that it wouldn't work that I haven't even tried!> > BTW -- calling your data frame "df" is a bad idea. There is a built-in > function named "df", and on occasion the result of naming some other > object "df" can be mysterious errors accompanied by opaque error > messages. > > cheers, > > Rolf Turner >
What's wrong with: result <- with(df, x/n) ? Do I misunderstand? (and what's the p = .065 or [[1]] have to do with the estimated prob, as you are not actually doing any test?) Finally, if you really do this sort of thing, ?mapply (and ?with) can be useful; e.g. you could have rewritten your loop as:> with(df,mapply(function(...)binom.test(...)$estimate,x,n,MoreArgs = list(p=.065)))probability of success probability of success probability of success 0.45454545 0.16000000 0.04166667 probability of success probability of success 0.15000000 0.28333333 Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Fri, Jul 29, 2016 at 1:52 AM, Alain D. via R-help <r-help at r-project.org> wrote:> Dear list, > > I have a dataframe df: > > df<-data.frame(x=c(5,32,18,3,17), n=c(11,200,432,20,60)) > > Now I want to run n=nrow binom.test() with x being the number of success and n > the number of trials and then store the results as a new VAR in df. > > I tried > > for (i in 1:nrow(df)){ > df$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 > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.