DPpackage (version 1.1-0)

nodal: Nodal Involvement Data

Description

This data set consider information on the presence of prostatic nodal involvement collected on 53 patients with prostate cancer reported by Brown (1980). For the sample of prostate cancer patients, a number of possible predictor variables were measured before surgery. The patients then had surgery to determine nodal involvement. It was required to see if nodal involvement could be accurately predicted from the predictor variables and which ones were most important.

Usage

data(nodal)

source

Brown, B.W. (1980) Prediction analysis for binary data. In Biostatistics Casebook. R.G. Miller, B. Efron, B.W. Brown and L.E. Moses (editors), 3-18. John Wiley.

References

Chib, S. (1995) Marginal Likelihood from the Gibbs output. Journal of the American Statistical Association, 90: 1313 - 1321.

Examples

# Data
      data(nodal)
      attach(nodal)
      lacid<-log(acid)

    # Initial state
      state <- NULL

    # MCMC parameters
      nburn<-5000
      nsave<-10000
      nskip<-10
      ndisplay<-100
      mcmc <- list(nburn=nburn,nsave=nsave,nskip=nskip,ndisplay=ndisplay,
                   tune=1.1)


    # Prior distribution
      prior <- list(alpha=1,beta0=c(0,rep(0.75,5)),
                    Sbeta0=diag(c(100,rep(25,5)),6))

    # Fit the model
      fit1 <- DPbinary(ssln~age+lacid+xray+size+grade,prior=prior,mcmc=mcmc,
                       state=state,status=TRUE) 
      fit1