# [R] binom.test Classic List Threaded 6 messages Open this post in threaded view
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## [R] binom.test

 R-experts: A quick question, please. >From a lab exp, I got 12 positives out of 50. To get 90% CI for this , I think binom.test might be the one to be used. Is there a better way or function to calculate this? > binom.test(x=12, n=50, p=12/50, conf.level = 0.90)         Exact binomial test data:  12 and 50 number of successes = 12, number of trials = 50, p-value = 1 alternative hypothesis: true probability of success is not equal to 0.24 90 percent confidence interval:  0.1447182 0.3596557 sample estimates: probability of success                   0.24 thx much ej ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: [R] binom.test

 Ethan Johnsons wrote: > R-experts: > > A quick question, please. > >>From a lab exp, I got 12 positives out of 50. > To get 90% CI for this , I think binom.test might be the one to be used. > Is there a better way or function to calculate this? > >> binom.test(x=12, n=50, p=12/50, conf.level = 0.90) > >         Exact binomial test > > data:  12 and 50 > number of successes = 12, number of trials = 50, p-value = 1 > alternative hypothesis: true probability of success is not equal to 0.24 > 90 percent confidence interval: >  0.1447182 0.3596557 > sample estimates: > probability of success >                   0.24 You might consider binconf() in the Hmisc package too: library(Hmisc) binconf(12, 50, method="all")            PointEst    Lower    Upper Exact          0.24 0.130610 0.381691 Wilson         0.24 0.142974 0.374127 Asymptotic     0.24 0.121621 0.358379 > thx much > > ej > > ______________________________________________ > [hidden email] mailing list > 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. -- Chuck Cleland, Ph.D. NDRI, Inc. 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 512-0171 (M, W, F) fax: (917) 438-0894 ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: [R] binom.test

 In reply to this post by Ethan Johnsons On 19-Oct-06 Ethan Johnsons wrote: > R-experts: > > A quick question, please. > >>From a lab exp, I got 12 positives out of 50. > To get 90% CI for this , I think binom.test might be > the one to be used. > Is there a better way or function to calculate this? What do you mean by "better"? For a symmetrical 2-sided exact binomial confidence interval, binom.test gives the result quickly and, to within the precision of pbinom, correctly (as I've just verified by hand!). And you can get 1-sided CIs by setting the 'alternative' option, or asymmetrical CI's by finding the two 1-sided CIs (e.g. for conf.level = 0.03 and 0.07) that you want. What do you want to improve on? >> binom.test(x=12, n=50, p=12/50, conf.level = 0.90) > >         Exact binomial test > > data:  12 and 50 > number of successes = 12, number of trials = 50, p-value = 1 > alternative hypothesis: true probability of success is not equal to > 0.24 > 90 percent confidence interval: >  0.1447182 0.3596557   r<-12 ; n<-50   1-pbinom(r-1,n, 0.14471815)    0.04999999   1-pbinom(r-1,n, 0.14471816)    0.05000001   pbinom(r,n, 0.35965569)    0.05000001   pbinom(r,n, 0.35965570)    0.05   pbinom(r,n, 0.35965571)    0.04999998 > sample estimates: > probability of success >                   0.24 > > thx much > > ej Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[hidden email]> Fax-to-email: +44 (0)870 094 0861 Date: 19-Oct-06                                       Time: 16:53:19 ------------------------------ XFMail ------------------------------ ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: [R] binom.test

 Thx much for the feedback. It is a big help. ej On 10/19/06, Ted Harding <[hidden email]> wrote: > On 19-Oct-06 Ethan Johnsons wrote: > > R-experts: > > > > A quick question, please. > > > >>From a lab exp, I got 12 positives out of 50. > > To get 90% CI for this , I think binom.test might be > > the one to be used. > > Is there a better way or function to calculate this? > > What do you mean by "better"? For a symmetrical 2-sided > exact binomial confidence interval, binom.test gives the > result quickly and, to within the precision of pbinom, > correctly (as I've just verified by hand!). > > And you can get 1-sided CIs by setting the 'alternative' > option, or asymmetrical CI's by finding the two 1-sided > CIs (e.g. for conf.level = 0.03 and 0.07) that you want. > > What do you want to improve on? > > >> binom.test(x=12, n=50, p=12/50, conf.level = 0.90) > > > >         Exact binomial test > > > > data:  12 and 50 > > number of successes = 12, number of trials = 50, p-value = 1 > > alternative hypothesis: true probability of success is not equal to > > 0.24 > > 90 percent confidence interval: > >  0.1447182 0.3596557 > >   r<-12 ; n<-50 > >   1-pbinom(r-1,n, 0.14471815) >    0.04999999 > >   1-pbinom(r-1,n, 0.14471816) >    0.05000001 > > >   pbinom(r,n, 0.35965569) >    0.05000001 > >   pbinom(r,n, 0.35965570) >    0.05 > >   pbinom(r,n, 0.35965571) >    0.04999998 > > > > sample estimates: > > probability of success > >                   0.24 > > > > thx much > > > > ej > > Best wishes, > Ted. > > -------------------------------------------------------------------- > E-Mail: (Ted Harding) <[hidden email]> > Fax-to-email: +44 (0)870 094 0861 > Date: 19-Oct-06                                       Time: 16:53:19 > ------------------------------ XFMail ------------------------------ > ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.