无法在R中的包fanplot中找到运行示例的ew.txt文件

Question

I am trying to follow an example in the package fanplot but I cannot find the ew.txt file. I would be grateful for your help.

data(ew)
plot(ew)

## Not run: 
plot(ew.mcmc)

##
##Create your own (longer) MCMC sample
##
# data
r <- diff(log(ew))
r <- ts(exp(r) - 1, start(ew))

library("R2OpenBUGS")
# write model file:
ew.bug <- dget(system.file("model", "ew.txt", package = "fanplot"))
write.model(ew.bug, "ew.txt")
# take a look:
file.show("ew.txt")
# run openbugs
ew.mcmc <- bugs(data = list(N = length(r), H = 25, r = c(r), p = c(ew)),
                inits = list(list(a = exp(12), psi = 0.5, itau2 = 0.5)),
                param = c("alpha", "psi", "tau", "r.new", "p.new", "y.sim"),
                model = "ew.txt", 
                n.iter = 11000, n.burnin = 1000, n.chains = 1, n.thin = 1)

## End(Not run)

Answer 1

The file is in R_LIBS/fanplot/model/ where R_LIBS is the location of your package library.

In the example code, the file is found via system.file() :

system.file("model", "ew.txt", package = "fanplot")

and then the next line writes the model to a the file ew.txt in the working directory. It is not clear which ew.txt you want. If the one that comes with the package find it in R_LIBS as above. Or download the source tarball from CRAN (the tar.gz from the package page on cran .

Answer 2

When you run this code in an interactive session, use getwd to see what your working directory is. This should be the directory which contains the saved text file.