[R] R2WinBUGS: Error in bugs(program="openbugs") but not openbugs()

[Yuelin Li]

I get an error when I call bugs(..., program="OpenBUGS",
bugs.directory="c:/Program Files/OpenBUGS/OpenBUGS312"),
expecting, as suggested in help(bugs), that it would fit the
model with openbugs() via BRugs.

 > help(bugs)
 ... either winbugs/WinBUGS or openbugs/OpenBUGS, the latter
 makes use of function openbugs and requires the CRAN package
 BRugs. ...

However, it works fine when I directly call openbugs().  All
other things are exactly the same.  It seems that (in my
settings) bugs(program="OpenBUGS") works differently than
openbugs().  Am I doing something wrong with bugs()?   Or
there is something wrong with my OpenBUGS installation?

I am using R-2.12.0, R2WinBUGS 2.1-16 (2009-11-06), OpenBUGS
3.1.2 rev 668 (2010-09-28), and BRugs 0.5-3 (2009-11-06)  on
a Windows XP machine.

Yuelin.

------- R file ---------
require(R2WinBUGS)
require(BRugs)
# Example in Albert (2007).  Bayesian Computation with R.  Springer.
# pp. 237-238.  Prior = beta(0.5, 0.5), observe Binom(n, p) 
# y=7 successes out of a sample of n=50.  Estimate p.
y <- 7
n <- 50
alpha <- 1.0 
beta <- 1.0 
data <- list("y", "n", "alpha", "beta")
inits <- function() { list(p = runif(1)) }
param <- "p"
# this works
Albert.bugs <- openbugs(data=data, inits=inits, parameters.to.save=param, model.file = "C:/tryR/WinBUGS/Albert11.txt", n.chains=3, n.iter=500)
print(Albert.bugs, digits.summary = 4)
# this fails
Albert.bugs <- bugs(data=data, inits=inits, parameters.to.save=param, model.file="C:/tryR/WinBUGS/Albert11.txt", n.chains=3, n.iter=500, program="OpenBUGS")

------- BUGS file: Albert11.txt ------
model 
{ 
y ~ dbin(p, n)
p ~ dbeta( alpha, beta )
}


 
     =====================================================================
     
     Please note that this e-mail and any files transmitted with it may be 
     privileged, confidential, and protected from disclosure under 
     applicable law. If the reader of this message is not the intended 
     recipient, or an employee or agent responsible for delivering this 
     message to the intended recipient, you are hereby notified that any 
     reading, dissemination, distribution, copying, or other use of this 
     communication or any of its attachments is strictly prohibited.  If 
     you have received this communication in error, please notify the 
     sender immediately by replying to this message and deleting this 
     message, any attachments, and all copies and backups from your 
     computer.