Confidence Intervals for Binomial Probabilities
DESCRIPTION:
Produces 1-alpha confidence intervals for binomial probabilities.
USAGE:
binconf(x, n, alpha=0.05,
method=c("wilson","exact","asymptotic","all"),
include.x=FALSE, include.n=FALSE, return.df=FALSE)
ARGUMENTS:
- x
-
vector containing the number of "successes" for binomial variates
- n
-
vector containing the numbers of corresponding observations
- alpha
-
probability of a type I error, so confidence coefficient = 1-alpha
- method
-
character string specifing which method to use. The "all" method only
works when
x and n are length 1. The "exact" method uses the F distribution
to compute exact (based on the binomial cdf) intervals; the
"wilson" interval is score-test-based; and the "asymptotic" is the
text-book, asymptotic normal interval. Following Agresti and
Coull, the Wilson interval is to be preferred and so is the
default.
- include.x
-
logical flag to indicate whether
x
should be included in the
returned matrix or data frame
- include.n
-
logical flag to indicate whether
n
should be included in the
returned matrix or data frame
- return.df
-
logical flag to indicate that a data frame rather than a matrix be
returned
VALUE:
a matrix or data.frame containing the computed intervals and,
optionally,
x
and
n
.
AUTHOR(S):
Rollin Brant, Modified by Frank Harrell and
Brad Biggerstaff
Centers for Disease Control and Prevention
National Center for Infectious Diseases
Division of Vector-Borne Infectious Diseases
P.O. Box 2087, Fort Collins, CO, 80522-2087, USA
bkb5@cdc.gov
REFERENCES:
A. Agresti and B.A. Coull, Approximate is better than "exact" for
interval estimation of binomial proportions,
American Statistician,
52:119–126, 1998.
R.G. Newcombe, Logit confidence intervals and the inverse sinh
transformation,
American Statistician,
55:200–202, 2001.
L.D. Brown, T.T. Cai and A. DasGupta, Interval estimation for
a binomial proportion (with discussion),
Statistical Science,
16:101–133, 2001.
EXAMPLES:
binconf(0:10,10,include.x=TRUE,include.n=TRUE)
binconf(46,50,method="all")