mHP.btilde {ASSISTant} | R Documentation |
Compute the futility boundary (modified Haybittle-Peto) for the first two stages
Description
The futility boundary is computed by
solving (under the alternative)
Usage
mHP.btilde(beta, cov.J)
Arguments
beta |
the type II error |
cov.J |
the 3 x 3 covariance matrix |
Details
where the superscripts denote the stage and is the
fraction of the type I error (
) spent and
is the type II error. We make use of the joint normal density of
(the overall group) at each of the three stages and the
fact that the
is merely a translation of
. So here the calculation is based on a mean of zero and
has to be translated during use!
[Package ASSISTant version 1.4.3 Index]