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MCMC Error in CAR modelling

Posted: Thu Apr 15, 2010 10:32 am
by Karen
Hi MLwiN forum users,

I am hoping that someone may be able to help me. I have been using MLwiN for the last couple of years to fit multi-level models. I am now interested in fitting spatial models.

I have been following the guidance on Chapter 16 of the MCMC estimation in MLwiN manual and managed to fit a spatial multiple membership model. However, I am keen to see if a CAR model is more appropriate for my problem but when I try to fit this model I get the error message:

MCMC Error 0243: The ith neighbouring unit for area j is not a known area(MCMC)

where i and j are not always the same when I try and fit the model. However, i is commonly 1. I have checked area j and neighbour i to see if this error makes sense and the neighbour ID appears appropriate, as does the area number. I tried looking for error 0243 using search engines but couldn't find anything referring to this. Has anyone come across this error? Am I just doing something stupid with my data? I am fairly new to spatial regression analysis so would appreciate any guidance. It may just be that my data set is too large to cope with this problem in MLwiN- I have about 6500 areas with up to a possible 39 neighbours.

Cheers,
Karen

Re: MCMC Error in CAR modelling

Posted: Fri May 21, 2010 1:54 pm
by billb
Hi Karen,
I could take a look if you were happy to send on the worksheet. Note i and j might refer to the areas in the order the software receives them and not the labels they have.
Bill.