Represents the randomization procedure Chen's Design.
chenPar(N, mti = N, p = 0.5, groups = LETTERS[1:2])integer for the total sample size of the trial.
maximum tolerated imbalance in patient numbers during the trial.
success probability of the biased coin (e.g. in Efron's Biased Coin Design).
character vector of labels for the different treatments.
S4 object of the class chenPar.
Flip a biased coin with probability p in favour of the treatment
which is allocated less frequently as long as the difference in group sizes doesn`t
exceed the mti. If the mti is reached a deterministic
allocation is done, so that the difference in group sizes is reduced.
If both treatments have been assigned equally often a fair coin is tossed.
Chen Yung-Pin (1999) Biased coin design with imbalance tolerance. Comm. in Stat., 15, 953-975.
Other randomization procedures: abcdPar,
bbcdPar, bsdPar,
crPar, createParam,
ebcPar, gbcdPar,
hadaPar, mpPar,
pbrPar, rarPar,
rpbrPar, rtbdPar,
tbdPar, udPar