binom.test: Exact Tests for Proportions

Description

The binom.test function performs an exact test of a simple null hypothesis about the probability of success in a Bernoulli experiment from summarized data or from raw data. The mosaic binom.test provides wrapper functions around the function of the same name in stats. These wrappers provide an extended interface (including formulas).

Usage

binom.test(x, n, p = 0.5, alternative = c("two.sided", "less", "greater"),
  conf.level = 0.95, ci.method = c("Clopper-Pearson", "binom.test", "Score",
  "Wilson", "prop.test", "Wald", "Agresti-Coull", "Plus4"),
  data = parent.frame(), success = NULL, ...)

Arguments

count of successes, length 2 vector of success and failure counts, a formula, or a character, numeric, or factor vector containing raw data.

sample size (successes + failures) or a data frame (for the formula interface)

probability for null hypothesis

alternative

type of alternative hypothesis

conf.level

confidence level for confidence interval

ci.method

a method to use for computing the confidence interval (case insensitive and may be abbreviated). See details below.

data

a data frame (if missing, n may be a data frame)

success

level of variable to be considered success. All other levels are considered failure.

...

additional arguments (often ignored)

Value

an object of class htest

Details

binom.test is a wrapper around binom.test from the base package to simplify its use when the raw data are available, in which case an extended syntax for binom.test is provided. See the examples.

Also, five confidence interval methods are provided: [object Object],[object Object],[object Object],[object Object],[object Object]

Examples

Run this code

# Several ways to get a confidence interval for the proportion of Old Faithful
# eruptions lasting more than 3 minutes.
data(faithful)
binom.test(faithful$eruptions > 3)
binom.test(97, 272)
binom.test(c(97, 272-97))
faithful$long <- faithful$eruptions > 3
binom.test(faithful$long)
binom.test(resample(1:4, 400), p=.25)
binom.test(~ long, data=faithful)
binom.test(~ long, data=faithful, ci.method="Wald")
binom.test(~ long, data=faithful, ci.method="Plus4")
with(faithful, binom.test(~long))
with(faithful, binom.test(long))