write.model {R2WinBUGS}R Documentation

Creating a WinBUGS model file

Description

Convert R function to a WinBUGS model file

Usage

write.model(model, con = "model.bug")

Arguments

model R function containg the BUGS model in the BUGS model language, for minor differences see Section Details.
con passed to link{writeLines} which actually writes the model file

Details

The fact that bugs models follow closely to S (R) syntax is used. It should be possible to write most BUGS models as R functions.

As a difference, BUGS syntax allows truncation specification like this: dnorm(...) I(...) but this is illegal in R. To overcome this incompatibility, use %_% before I(...): dnorm(...) %_% I(...). The dummy operator %_% will be removed before the BUGS code is saved.

Value

Nothing, but as a side effect, the model file is written.

Author(s)

original idea by Jouni Kerman, modified by Uwe Ligges

See Also

bugs

Examples

## Same "schoolsmodel" that is used in the examples in ?bugs:
schoolsmodel <- function(){
    for (j in 1:J){
        y[j] ~ dnorm (theta[j], tau.y[j])
        theta[j] ~ dnorm (mu.theta, tau.theta)
        tau.y[j] <- pow(sigma.y[j], -2)
    }
    mu.theta ~ dnorm (0.0, 1.0E-6)
    tau.theta <- pow(sigma.theta, -2)
    sigma.theta ~ dunif (0, 1000)
}

## some temporary filename:
filename <- file.path(tempdir(), "schoolsmodel.bug")
## write model file:
write.model(schoolsmodel, filename)
## and let's take a look:
file.show(filename)

[Package R2WinBUGS version 2.0-4 Index]