Drift

Calculate the drift value with given upper bounds (z-values), times of test, and power.

group sequential design

This is a core implementation of 'SAS' procedures for linear models - GLM, REG, ANOVA, TTEST, FREQ, and UNIVARIATE. Some R packages provide Type II and Type III SS. However, the results of nested and complex designs are often different from those of 'SAS'. Different results do not necessarily mean incorrectness. However, many want the same results as 'SAS'. This package aims to achieve that.
Reference: Littell RC, Stroup WW, Freund RJ (2002, ISBN:0-471-22174-0).

Kyun-Seop Bae

sasLM

'SAS' Linear Model

Drift function

<dl> <dt>bi</dt>
<dd>upper bound z-values</dd> <dt>ti</dt>
<dd>times of test. These should be in the range of [0, 1]. If omitted, equal intervals are assumed.</dd> <dt>Power</dt>
<dd>target power at the final test</dd></dl>

Arguments

Author

Drift defined by Lan and DeMets for Group Sequential Design — Drift

<dl>

 <dt>bi</dt>
<dd>upper bound z-values</dd>

 <dt>ti</dt>
<dd>times of test. These should be in the range of [0, 1]. If omitted, equal intervals are assumed.</dd>

 <dt>Power</dt>
<dd>target power at the final test</dd>

</dl>

Drift: Drift defined by Lan and DeMets for Group Sequential Design

Description

Usage

Value

Arguments

Author

Details

References

Examples