[R] R2WinBUGS sending variables as factors
Uwe Ligges
ligges at statistik.uni-dortmund.de
Fri Jan 4 15:58:42 CET 2008
James,
the first non-regular message you got in the output was:
"made use of undefined node nSeaW",
so what about defining nSeaW (or did you mean to write mSeaW)?
If this is not the problem, please provide the data so that we can try
to reproduce your error, as the psoting guide (of R-help) ask you to do.
Please do not crosspost (at least not on R-help), the posting guide asks
you not to do so.
Best,
Uwe Ligges
James.Dell at csiro.au wrote:
> Hello R and BUGS users,
>
> I am writing a heirarchical model in R to send to BUGS via R2WinBUGS and
> I am finding it difficult to get the model to run. I seem to be having
> two problems.
> 1) I can't seem to send variables classed as factors (Month), is there a
> way do this?
> 2) Checking the Log in WinBUGS I can see that the model is Syntactically
> correct, but Bugs is not able to recognise the the initial values for
> each of the chains.
>
> I have been following the examples provided in the R vignette for
> R2WinBUGS and I am a little stumped on what do do next. Any suggestions
> and help will be greatly appreciated.
> The Model and the R Code have been using are below. The Error from
> WinBUGS is at the end of this mail.
>
> Kind Regards
>
> Jim Dell
> Phd Candidate
> Quantitative Marine Science
> University of Tasmania and CSIRO Marine and Atmospheric Research
> ph +62 3 6232 5182
> mb +61 429 32 5182
>
> model
> {
> #Centre variables
> mSeaW <- mean(SeaW[])
> s_dSeaW <- sd(SeaW[])
>
> #normalise Variables
> nSeaWiFS <- mSeaW/s_dSeaW
>
> for(i in 1:N) {
> log(lambda[i]) <- delta0 + alpha1 * Month[i] + alpha2 * Lat[i] +
> beta1 * (SeaW[i] - nSeaW)
>
> logit(p[i]) <- gamma0
> mu[i, 1] <- 0
> mu[i, 2] <- lambda[i]
> mu.i[i] <- mu[i, index[i]]
> index[i] ~ dcat(theta[i, 1:2])
> theta[i, 1] <- p[i]
> theta[i, 2] <- 1 - p[i]
> # mixture
> YFTCPUE[i] ~ dpois(mu.i[i])
>
> }
>
> # recalculate the original intercept term
> Intercept <- delta0 - beta1 * nSeaW
>
> #prior on regression coefficients
> beta1 ~ dnorm(0,1.0E-6)
> alpha2 ~ dnorm(0,1.0E-6)
> alpha1 ~ dnorm(0, 1.0E-6)
> delta0 ~ dnorm(0, 1.0E-6)
> gamma0 ~ dnorm(0, 1.0E-6)
> }
>
> ##R Code
>
> library(R2WinBUGS)
> library(Rlab)
>
> #sampling functions
> #get a subset of the data to use in the modelling process
> LearnSamp <- function (dBUGS) # data frame of the variables of interest
> {
> rnames<- row.names(dBUGS)
> sampRows <- sample(rnames,900)
> learnSamp <- subset(dBUGS,rnames%in%sampRows)
> }
>
>
> #maybe not needed index.inits <- function ()
> # get data into correct form for R2WinBUGS
>
> d <-LearnSamp(dBUGS)
> YFTCPUE <- d$CPUE
> Month <- d$Month
> Lat <- d$Lat
> SeaW <- d$SeaW
> N <- nrow(d)
>
>
> data <- list("N", "YFTCPUE","Lat","SeaW")
> #,"Month" #Month Taken out so that model runs
>
>
> #create initial values for the coefficients in the model (this is model
> specific)
> #construct inits for the three chain
>
> inits1 <- list(gamma0 = 0, delta0 = 0,beta1 = 0, alpha1 = 0, alpha2 = 0,
> index = rbern(J,0.5)+1)
> inits2 <- list(gamma0 = 0, delta0 = 0,beta1 = 0, alpha1 = 0, alpha2 = 0,
> index = rbern(J,0.5)+1)
> inits3 <- list(gamma0 = 0, delta0 = 0,beta1 = 0, alpha1 = 0, alpha2 = 0,
> index = rbern(J,0.5)+1)
>
> inits <- list(inits1,inits2,inits3)
>
>
>
> ## these data.frames need to be trimmed so that we can send varibles to
> WinBUGS
>
> parameters <- c("gamma0", "delta0", "beta1", "alpha1","alpha2", "index")
> model <- bugs(data, inits, parameters,
> model.file = "C:/Documents and Settings/del125/My Documents/PhD
> data/ETBF - BUGS/CodeR2BUGS/MinusMonthSeaWiFS.bug",
> codaPkg = FALSE, bugs.directory = "C:/Program Files/WinBUGS14/", debug
> =TRUE)
>
>
>
> ##And the Error Message from WinBUGS
>
> model is syntactically correct
>
> data(C:/Program Files/R/R-2.6.0/data.txt)
>
> data loaded
>
> compile(3)
>
> made use of undefined node nSeaW
>
> inits(1,C:/Program Files/R/R-2.6.0/inits1.txt)
>
> command #Bugs:inits cannot be executed (is greyed out)
>
> inits(2,C:/Program Files/R/R-2.6.0/inits2.txt)
>
> command #Bugs:inits cannot be executed (is greyed out)
>
> inits(3,C:/Program Files/R/R-2.6.0/inits3.txt)
>
> command #Bugs:inits cannot be executed (is greyed out)
>
> gen.inits()
>
> command #Bugs:gen.inits cannot be executed (is greyed out)
>
> thin.updater(3)
>
> update(334)
>
> command #Bugs:update cannot be executed (is greyed out)
>
> (error continues.....)
>
>
> [[alternative HTML version deleted]]
>
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