power_Binomial {PASSED}

Power Calculations for Two-Sample Test for Proportions

Description

Compute power of test, or determine parameters to obtain target power for equal and unequal sample sizes.

Usage

power_Binomial(n1 = NULL, n2 = NULL, power = NULL, sig.level = 0.05,
p1 = 0.5, p2 = 0.5, equal.sample = TRUE, alternative = c("two.sided", "one.sided"))

Arguments

n1

sample size in group 1, or sample size in each group if equal.sample = TRUE

n2

sample size in group 2

power

power of test (1 minus Type II error probability)

sig.level

significance level (Type I error probability)

p1

probability in group 1

p2

probability in group 2

equal.sample

equal sample sizes for two groups, see details

alternative

one- or two-sided test

Details

Exactly one of the parameters n1, n2, p1, p2, power, and sig.level must be passed as NULL, and that parameter is determined from the others. Notice that p1, p2, sig.level have non-NULL defaults, so NULL must be explicitly expressed if you want to compute them.

If equal.sample = TRUE is used, N in output will denote the number in each group.

Value

Object of class "power.htest", a list of the arguments (including the computed one) augmented with note and method elements.

Examples

# calculate power, equal sizes
power_Binomial(n1 = 100, p1 = 0.5, p2 = 0.7)
# calculate power, unequal sizes
power_Binomial(n1 = 150, n2 = 100, p1 = 0.5, p2 = 0.7)
# calculate n2
power_Binomial(n1 = 100, p1 = 0.5, p2 = 0.7, power = 0.9, equal.sample = FALSE)