[R-sig-eco] interpreting 0s and 1s from manyglm from mvabund

[Elizabeth Pringle]

Hi,

I am using code that worked beautifully to analyze a previous dataset using
manyglm in mvabund on a new dataset, and I am consistently getting results
of Dev = 0 and Pr(>Dev)=1 for both multivariate and univariate tests. My
plots do not indicate any particularly strong pattern in the data, so I am
tempted to interpret this as a non-significant result...but I wanted to
make sure it doesn't just indicate that I've somehow input the data
incorrectly. Especially since I get a bunch of NAs and NaNs farther down
the line if I go through my whole pipeline.

Code follows:
>glm.sug<-manyglm(dat~trtment,family="negative.binomial")
>results<-anova(glm.sug,resamp="pit.trap",p.uni="adjusted")
>results (here's where I see 0s and 1s)
>results$table
                 Res.Df Df.diff Dev Pr(>Dev)
(Intercept)          15      NA  NA       NA
trtment               14       1   0        1
> s=sort(results$uni.test[2,],index.return=T,decreasing=T)
> s$x[1:3]/sum(s$x)
        X..1          X.2        X..3
       NaN        NaN        NaN

Many thanks,
Beth

-- 
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Elizabeth G. Pringle
Michigan Society of Fellows
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