pow2 {agpower}R Documentation

Power for LWYY (fixed sample size)

Description

Function to compute power at one-sided Type I control level alp/2.

Usage

pow2(N, bta1, thta, L, alp = 0.05, ar = 0.5)

Arguments

N

Sample size.

bta1

log-transform of rate ratio.

thta

Variance of frailty parameter.

L

Number of events.

alp

Two-sided alpha-level.

ar

Allocation ratio (Number control / Total)

Value

The power given the input assumptions.

Examples


pow2(N = 500, bta1 = log(0.8), thta = 2, L = 1000, alp = 0.05)
pow2(N = 500, bta1 = log(0.8), thta = 3, L = 1000, alp = 0.05)

if (require("dplyr") & require("tidyr")) {

  assumptions = tibble(alp = 0.05) %>%
  crossing(
    thta = c(1),
    RR = c(0.6, 0.7, 0.8),
    L = c(1000, 1500, 2000),
    N = c(500, 1000)
  ) %>%
    mutate(pow = pow2(N = N, bta1 = log(RR), thta = thta, L = L, alp = alp))

  assumptions %>% data.frame()

}


[Package agpower version 0.1.2 Index]