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Error in solve.default(as.matrix(fit$hessian))
2 messages · Roman Luštrik, Gavin Simpson
On Mon, 2010-02-22 at 08:06 +0100, Roman Lu?trik wrote:
Dear list, I'm trying to construct a zero-inflated negative binomial model but I get greeted by an error. I haven't had the chance to try my dataset on different OSs or different R version, but I did mange to try that for the "cod parasite" data from Zuur et al book (Mixed effect models...) and I get a similar error (models with different formulas may or may not go through, depending on R version and the system). This is the error I get for the cod data. 1> nb1a <- zeroinfl(Intensity ~ Area*Year | Area*Year + Length, dist="negbin", link="logit", data=ParasiteCod2) Error in solve.default(as.matrix(fit$hessian)) : system is computationally singular: reciprocal condition number = 1.5208e-17 I get the same error on my data: frm <- formula(st_zir ~ obs_b+sonce+mraz+nmv | obs_b+sonce+mraz+nmv) nb <- zeroinfl(frm, dist="negbin", link="logit", data=zir2) Error in solve.default(as.matrix(fit$hessian)) : system is computationally singular: reciprocal condition number = 3.87086e-25 Has anyone any idea how to solve this? It has been suggested that it's something in my data, but I don't know what to think if the cod parasite data shows different success/failures on different versions for the same model.
Try fitting a simpler model; you may simply not have enough information in your data to fit such a complex model. HTH G
Cheers, Roman
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%