samplesizeFisherExact: Sample Size for Fisher's Exact Test for Two Proportions

In lrstat: Power and Sample Size Calculation for Non-Proportional Hazards and Beyond

Sample Size for Fisher's Exact Test for Two Proportions

Description

Obtains the sample size given power for Fisher's exact test for two proportions.

Usage

samplesizeFisherExact(
  beta = NA_real_,
  pi1 = NA_real_,
  pi2 = NA_real_,
  allocationRatioPlanned = 1,
  alpha = 0.05,
  max_n_search = 1000L,
  window = 10L
)

Arguments

beta	The type II error.
pi1	The assumed probability for the active treatment group.
pi2	The assumed probability for the control group.
allocationRatioPlanned	Allocation ratio for the active treatment versus control. Defaults to 1 for equal randomization.
alpha	The two-sided significance level. Defaults to 0.05.
max_n_search	The maximum sample size to search up to. If no sample size up to this value satisfies the windowed power criterion, an error is thrown.
window	The number of consecutive sample sizes that must all satisfy the power criterion to confirm the found sample size. This is to mitigate non-monotonicity of power in sample size for the exact test.

Value

A data frame with the following variables:

• alpha: The two-sided significance level.

• power: The power.

• n: The sample size.

• pi1: The assumed probability for the active treatment group.

• pi2: The assumed probability for the control group.

• allocationRatioPlanned: Allocation ratio for the active treatment versus control.

Author(s)

Kaifeng Lu, [e-mail]

Examples

(design1 <- samplesizeFisherExact(
  beta = 0.1, pi1 = 0.25, pi2 = 0.05, alpha = 0.05))

lrstat documentation built on May 13, 2026, 9:06 a.m.