EffFlexi: Initialization function for the "EffFlexi" class
In 0liver0815/onc-crmpack-test: Object-Oriented Implementation of CRM Designs

Initialization function for the "EffFlexi" class

1	EffFlexi(Eff, Effdose, sigma2, sigma2betaW, smooth = c("RW1", "RW2"), data)

`Eff`	the pseudo efficacy responses
`Effdose`	the corresponding dose levels for the pseudo efficacy responses
`sigma2`	the prior variance of the efficacy responses which can be specified with a single positive scalar or with two positive scalar values for the shape `a` and the rate `b` parameters of the inverse gamma distribution.
`sigma2betaW`	the prior variance of the random walk model used for smoothing which can be specified with a single positive scalar or with two positive scalars representing the shape `a` and the rate `b` parameter of the inverse gamma distribution.
`smooth`	used for smoothing data for this efficacy model. That is either the "RW1", the first-order random walk model or "RW2", the second-order random walk model is used of the mean efficacy responses.
`data`	the input data to update estimates of model parameters and follow the `DataDual` object class specification