cp is a function that computes the conditional power of a GSD.
Usage
cp(GSD)
Arguments
GSD
object of the classGSTobj or list with the following elements: K = number of stages, a = vector with futility boundaries (not supported yet), b = rejection boundaries, t = vector with information fractions, Imax = maximum information number, delta = effect size used for planning the trial; see example blow.
Value
cp returns the conditional power of a GSD.
References
O'Brien, PC, Fleming, TR (1979) ''A multiple testing procedure for clinical trials'',
Biometrics, 35 , 549-556
Schoenfeld, D (2001) ''A simple Algorithm for Designing Group Sequential Clinical Trials'',
Biometrics, 27, 972-974
# NOT RUN {##The following calculates the conditional power of a GSD.GSD <- list(K=4,a=rep(-8,4),b=c(4.333,2.963,2.359,2.014),t=c(0.25,0.5,0.75,1),Imax=0.22,delta=4)
cp(GSD)
# }