On Thu, 4 May 2006, Lucy Crooks wrote:
> Hi,
> I'm tying to fit a glm using quasi with variance=mu(1-mu) (to try and
> get "well behaved" residuals). I get an error message:
> "cannot find valid starting values, please specify some".
> I have tried using start= and specifying coefficients from a previous
> fit (with different error structure) but get the same message.
> What would be valid starting values?
What link are you using? You need 0 < mu < 1 (the actual function used is
validmu <- function(mu) all(mu>0) && all(mu<1)
plus any restriction from the unspecified link).
> I am using a 64 bit build R on a MacG5.
The version of R is more important here.
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
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