mc.est {CorrBin} | R Documentation |
The mc.est
function estimates the distribution of the number of
responses in a cluster under the assumption of marginal compatibility: information
from all cluster sizes is pooled. The estimation is performed independently for
each treatment group.
mc.est(cbdata)
cbdata |
a CBData object |
The EM algorithm given by Stefanescu and Turnbull (2003) is used.
A data frame giving the estimated pdf for each treatment and clustersize. It has the following columns:
Prob |
numeric, the probability of NResp responses in a cluster
of size ClusterSize in group Trt |
Trt |
factor, the treatment group |
ClusterSize |
numeric, the cluster size |
NResp |
numeric, the number of responses |
Aniko Szabo
Stefanescu, C. & Turnbull, B. W. (2003) Likelihood inference for exchangeable binary data with varying cluster sizes. Biometrics, 59, 18-24
data(shelltox) sh.mc <- mc.est(shelltox) library(lattice) xyplot(Prob~NResp|factor(ClusterSize), groups=Trt, data=sh.mc, subset=ClusterSize>0, type="l", as.table=TRUE, auto.key=list(columns=4, lines=TRUE, points=FALSE), xlab="Number of responses", ylab="Probability P(R=r|N=n)")