Nest survival: (maxstephalfit) PIRLS step-halvings failed to reduce deviance in pwrssUpdate
Hi Ben Thank you very much for your reply. If you click on this link, it should give you the data in a CSV file. https://sites.google.com/site/es263datahlp/habitat-type_example.csv Many thanks Elwyn
On 5 March 2015 at 03:11, Ben Bolker <bbolker at gmail.com> wrote:
Elwyn Sharps <e.sharps at ...> writes:
[snip]
I am using a nest survival model (glmer) with random effects and a
logistic
exposure link function, as described here:
glmer-for-known-fate-survival-modelling I am running a number of different models, with varying fixed effects.
Some
of them are running well, with no error or warning messages, however for other models, I am getting the following message: *Error: (maxstephalfit) PIRLS step-halvings failed to reduce deviance in pwrssUpdate* I'm not sure what is causing this error. I have tried to check the data
for
simple problems, however can't see anything that could be causing
trouble.
I've also tried running the model without the random effects. This
results
in a different error message: *Error: cannot find valid starting values: please specify some*
Example data doesn't seem to be attached: it may have been stripped by the mailing list software. Can you post it somewhere public and provide a URL? My guess it that there is something rather wonky about the data for this example, e.g. complete separation (for example, no individuals die for some combination of predictor variables). Hard to say without the data though. Ben Bolker
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