% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/Model-class.R
\docType{class}
\name{DualEndpointRW-class}
\alias{.DualEndpointRW}
\alias{DualEndpointRW-class}
\title{Dual endpoint model with RW prior for biomarker}
\description{
This class extends the \code{\linkS4class{DualEndpoint}} class. Here the
dose-biomarker relationship \eqn{f(x)} is modelled by a non-parametric
random-walk of first (RW1) or second order (RW2) (todo: warning: at the
moment only the first order random walk produces useful results).
}
\details{
That means, for the RW1 we assume
\deqn{\beta_{W,i} - \beta_{W,i-1} \sim Normal(0, \sigma^{2}_{\beta_{W}}),}
where \eqn{\beta_{W,i} = f(x_{i})} is the biomarker mean at the i-th dose
gridpoint \eqn{x_{i}}.
For the RW2, the second-order differences instead of the first-order
differences of the biomarker means follow the normal distribution.

The variance parameter \eqn{\sigma^{2}_{\beta_{W}}} is important because it
steers the smoothness of the function f(x): if it is large, then f(x) will
be very wiggly; if it is small, then f(x) will be smooth. This parameter can
either be fixed or assigned an inverse gamma prior distribution.

Usually this modelling will only make sense if a regular dose grid is used,
with equidistant grid points ensuring that the distance \eqn{x_{i} -
x_{i-1}} is the same for all grid positions \eqn{i}.
}
\section{Slots}{

\describe{
\item{\code{sigma2betaW}}{Contains the prior variance factor of the random walk
prior for the biomarker model. If it is not a single number, it can also
contain a vector with elements \code{a} and {b} for the inverse-gamma prior
on \code{sigma2betaW}.}

\item{\code{useRW1}}{for specifying the random walk prior on the biomarker level: if
\code{TRUE}, RW1 is used, otherwise RW2.}
}}
\examples{


model <- DualEndpointRW(mu = c(0, 1),
                        Sigma = matrix(c(1, 0, 0, 1), nrow=2),
                        sigma2betaW = 0.01,
                        sigma2W = c(a=0.1, b=0.1),
                        rho = c(a=1, b=1),
                        smooth="RW1")


}
\keyword{classes}

