find.c: Function to solve for a group sequential critical value at a...
In gsMeanFreq: Group Sequential Clinical Trial Designs for Composite Endpoints

find.c

R Documentation

Function to solve for a group sequential critical value at a given stage

Description

Computes the critical boundary value at the current analysis stage by solving a probability equation under a multivariate normal distribution. The boundary is chosen so that the incremental Type I error spent at the current stage equals a specified target value, conditional on previously determined boundaries.

Usage

find.c(previous.c, pi, corr)

Arguments

`previous.c`	Numeric value giving the critical boundary from the previous analysis stage.
`pi`	Target incremental Type I error to be spent at the current stage.
`corr`	Correlation matrix of the joint multivariate normal distribution of test statistics across analyses.