GroupSeq (version 1.0)

findDrift: Find drift resulting in power "confidenceLevel".

Description

The drift will be that value producing exit probability "confidenceLevel" at time t(n) given the bounds. If t(n) < 1, this is not the power of the study.

Usage

findDrift(n, t, t2, lowerBounds, upperBounds, confidenceLevel, drift, nMax)

Arguments

n

the number of analyses.

t

the vector of analysis time point on (0,1).

t2

is the second or information time scale, for covariances

lowerBounds

the vector of lower bounds (standardized).

upperBounds

the vector of upper bounds (standardized).

confidenceLevel

desired power respectively confidence level

drift

vector of drift parameters

nMax

Number of interim analyses is by default limited to nMax=25

Value

• drift
  computed drift

Details

This function directly calls computeDrift

See Also

groupseq, computeDrift

Examples

## fictious example
computeDrift(2, c(0.5,1.0), c(0.5,1.0), c(-8,-8), c(2.3,1.1), 0.3, 0, 25)
## with following result:
## [1] 0.5696356