R: Commonly used alpha-spending functions

SigP {esDesign}

R Documentation

Commonly used `\alpha`-spending functions

Description

The SigP() is used to calculate the reduced significant level based on several widely used \alpha-spending functions, such as the "Pocock", "Lan-DeMets", "O'Brein-Fleming" and "Power" functions.

Usage

SigP(alpha, Info, esFunction = "Pocock", gamma = 1)

Arguments

`alpha`	The overall Type I error rate
`Info`	The fraction of the observed information
`esFunction`	The specific `\alpha`-spending function. For example, `esFunction = "Pocock"` for the Pocock method, `esFunction = "LD"` for the Lan-Demets method, `esFunction = "OF"` for the O'Brein-Fleming method, and `esFunction = "Power"` for the Power method.
`gamma`	The parameter used in the Power method. The default value is `gamma = 1`.

Value

The reduced significant level

Examples

alpha <- 0.05
Info <- 0.5
esFunction = "OF"
SigP(alpha = alpha, Info = Info, esFunction = esFunction)