[R] mvabund package: errors using manyglm() and meanvar.plot()

2012-02-20 Thread Martijn Vandegehuchte
Dear R users, I am trying to analyze multivariate abundance data using the mvabund package, but errors occur for several functions. I created a mvabund object named faunadat consisting of 8 dependent variables each containing 64 positive integer values (bact, fung, plant, omn, pred, orib, meso,

[R] p-value for fixed effect in generalized linear mixed model

2008-02-20 Thread Martijn Vandegehuchte
if spikes is not having a significant effect on aphids, then why the above mentionned p-value generated by anova in R? Can anyone explain this? Please find the dataset in the attachment. Many thanks beforehand, Martijn. -- Martijn Vandegehuchte Ghent University Department Biology

[R] Cholmod error `matrix not positive definite'

2008-02-14 Thread Martijn Vandegehuchte
in SAS with proc glimmix... Does someone have experience with this type of problem? Thank you in advance, Martijn. -- Martijn Vandegehuchte Ghent University Department Biology Terrestrial Ecology Unit K.L.Ledeganckstraat 35 B-9000 Ghent telephone: +32 (0)9/264 50 84 e-mail: [EMAIL