[R] Extreme AIC or BIC values in glm(), logistic regression

[Gad Abraham]

Maggie Wang wrote:
> Hi, Dieter, Gad, and all,
> 
> Thank you very much for your reply!  
> 
> So here is my data,  you can copy it into a file names "sample.txt"

Hi Maggie,

With this data (allowing for more iterations) I get:

> lr <- glm(fo, family=binomial(link=logit), data=matrix, 
control=glm.control(maxit=100))
Warning message:
In glm.fit(x = X, y = Y, weights = weights, start = start, etastart =
etastart,  :
   fitted probabilities numerically 0 or 1 occurred

which indicates, as Thomas has said, perfect separation, which occurs
because you're trying to fit too many variables with not enough data.

Cheers,
Gad

-- 
Gad Abraham
MEng Student, Dept. CSSE and NICTA
The University of Melbourne
Parkville 3010, Victoria, Australia
email: gabraham at csse.unimelb.edu.au
web: http://www.csse.unimelb.edu.au/~gabraham