computeConfidenceIntervall {GroupSeq} | R Documentation |
Computes confidence intervals, see Kim & DeMets 87. Given n interim analyses, bounds for the first n-1 and the standardized statistic for the nth, the function finds drift parameters satisfying confidence limit equations.
computeConfidenceIntervall(confidenceLevel, Zvalue, n, t, t2, lowerBounds, upperBounds, nMax)
confidenceLevel |
is confidence level. |
Zvalue |
is the Z statistic at the most recent analysis. |
n |
is the number of analyses. |
t |
is the vector of analysis time point on (0,1). |
t2 |
is the second or information time scale, for covariances |
lowerBounds |
is the vector of lower bounds (standardized). |
upperBounds |
is the vector of upper bounds (standardized). |
nMax |
maximum Number of interim analyses (default: nMax=25) |
confidenceLimit |
the calculated confidence interval |
This function is meant to be called in context of using groupseq
Roman Pahl
Kim & DeMets 1987 Biometrics http://www.biostat.wisc.edu/landemets/
## fictious example computeConfidenceIntervall(0.05, 1.7, 2, c(0.5,1.0), c(0.5,1.0), c(-1,0), c(1,2), 25) ## with following result: # [1] 1.115315 1.264942