curtail {seqmon}

Generic function that calculates the probability to declare efficacy at the end of study given the Z value at the current look

Description

Calculates the probability to declare efficacy at the end of study given the Z value at the current look

Usage

curtail(lower.boundary,upper.boundary,look,t,noncen,current=lower.boundary[look])

Arguments

lower.boundary

lower boundaries

upper.boundary

upper boundaries

look

current look number

t

time of looks

noncen

noncentrality parameter

current

current Z statistic

Value

numeric

Examples

t<-c(0.33,0.67,1)
f<- function(t) 0.025*t^4
g<-function(t) 0.20*t^3
a<-f(t)
b<-g(t)
noncen<-pnorm(0.975)+pnorm(0.8)
curtail(b,a,1,t,noncen)