alpha2boundary: Convert cumulative alpha levels to normal critical boundaries

In triggerstrategy: Trigger Strategy in Clinical Trials

Convert cumulative alpha levels to normal critical boundaries

Description

This function converts cumulative alpha levels into normal critical boundaries.

Usage

alpha2boundary(
  alphas,
  t,
  initIntvl = c(1, 2 * stats::qnorm(p = alphas[1], lower.tail = FALSE))
)

Arguments

alphas	a list of cumulative errors from some error spending functions
t	a vector of information times
initIntvl	a pair of numbers as the lower and upper bounds of critical boundaries, used for stats::uniroot function

Details

The current version of ldbounds::ldBounds may not work for Hwang-Shih-DeCani boundaries.

Value

a vector of critical boundaries

Author(s)

Jiangtao Gou

Examples

library(ldbounds)
tvec <- c(0.5,1)
result <- ldbounds::ldBounds(t=tvec, iuse=1, alpha=0.05, sides=1)
print(result$upper.bounds)
bd <- alpha2boundary(alphas = result$exit.pr, t=tvec)
print(bd)

triggerstrategy documentation built on July 9, 2023, 5:25 p.m.