MCMCglmm Bivariate Binary Model

Hi All,

  I attempted to fit a bivariate binary model similar to the example in
the Tutorial:

prior = list(R = list(V = diag(2), n = 0, fix = 2),
             G = list(G1 = list(V = diag(2), n = 1)))

model5 <- MCMCglmm(cbind(ANYHR, ANYPO) ~ trait - 1, random =
~us(trait):PROGRAM, rcov = ~idh(trait):units, family=c("categorical",
"categorical"), data = radars, prior = prior, verbose = FALSE)

Error in MCMCglmm(cbind(ANYHR, ANYPO) ~ trait - 1, random =
~us(trait):PROGRAM,  :
  ill-conditioned G/R structure: use proper priors if you haven't or
rescale data if you have

  In this dataset, one of the four cells in the 2x2 table is empty:

   Cell Contents
|-------------------------|
|                   Count |
|-------------------------|

Total Observations in Table:  21335

             | ANYPO
       ANYHR |        0  |        1  | Row Total |
-------------|-----------|-----------|-----------|
           0 |        0  |     8999  |     8999  |
-------------|-----------|-----------|-----------|
           1 |     6458  |     5878  |    12336  |
-------------|-----------|-----------|-----------|
Column Total |     6458  |    14877  |    21335  |
-------------|-----------|-----------|-----------|

  Is there a way to change the specification for prior to make this work?

thanks,

Chuck

Chuck Cleland, Ph.D.
NDRI, Inc. (www.ndri.org)
71 West 23rd Street, 8th floor
New York, NY 10010
tel: (212) 845-4495 (Tu, Th)
tel: (732) 512-0171 (M, W, F)
fax: (917) 438-0894