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) [1] 0.04999999 1-pbinom(r-1,n, 0.14471816) [1] 0.05000001 pbinom(r,n, 0.35965569) [1] 0.05000001 pbinom(r,n, 0.35965570) [1] 0.05 pbinom(r,n, 0.35965571) [1] 0.04999998 > sample estimates: > probability of success > 0.24 > > thx much > > ej Best wishes, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 19-Oct-06 Time: 16:53:19 ------------------------------ XFMail ------------------------------ ______________________________________________ R-help@stat.math.ethz.ch 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.
