| initLocPeak {gsrsb} | R Documentation |
Find the Location of Maximum, Standard OBF and POC
Description
Calculate the location of maximal tyep I error of the standard O'Brien-Fleming and Pocock refined secondary boundaries.
Usage
initLocPeak(alpha, tVec, cvec, type = 2, initIntvl = c(1, 4))
Arguments
alpha |
type I error. |
tVec |
information vector. |
cvec |
primary group sequential boundary. |
type |
type of the test procedure for the secondary endpoint. O'Brien- Fleming (OBF) type error spending funciton is 1, Pocock (POC) type error spending funciton is 2. |
initIntvl |
computing paramter, a pair of numbers containing the end-points of the interval to be searched for the root. |
Details
This function search the location of the maximal point, in order to calculate the standard (origiinal) O'Brien-Fleming (OBF) and Pocock (POC) refined secondary boundaries.
Value
location of maximum, a number between 1 and the number of interims
Author(s)
Jiangtao Gou
References
O'Brien, P. C., and Fleming, T. R. (1979). A multiple testing procedure for clinical trials. Biometrics 35, 549-556.
Pocock, S. J. (1977). Group sequential methods in the design and analysis of clinical trials. Biometrika 64, 191-199.
Tamhane, A. C., Gou, J., Jennison, C., Mehta, C. R., and Curto, T. (2018). A gatekeeping procedure to test a primary and a secondary endpoint in a group sequential design with multiple interim looks. Biometrics, to appear.
See Also
SecondaryBoundary, ldInitLocBeak
Examples
require(mvtnorm)
K <- 8
gammaVec <- sqrt((1:K)/K)
tVec <- gammaVec^2
alpha <- 0.025
c <- 2.072274
cvec <- c/gammaVec
loc <- initLocPeak(alpha,tVec,cvec,type=2,initIntvl=c(1,3))