Hello All,
I'm interested in using the mantel()and mantel.partial() functions in the
'vegan' R package to examine fish morphology in several lakes with respect to
distance between lakes, lake elevation (above sea level) and various habitat
measures. For example, several authors have postulated
On 1/10/09 20:36 PM, Sarah Goslee sarah.gos...@gmail.com wrote:
I can only speak for the mantel() within ecodist, but I can tell you that it
will not take full matrices - the upper triangle will be dropped. You could
roll your own very easily, but it would be exceedingly slow, eg:
mat1 -
Dear Steve,
If the direction is important, you can use that information as a
separate matrix with signs to scale up its effect. Because distance
can't be negative, you might end up with numbers hard to interpret.
Yours,
Peter
Péter Sólymos
Alberta Biodiversity Monitoring Institute
Department
Hi all,
1st time user here!
I am an ecologist working with marine fouling assemblages. I just got a paper
back for revision. I am working with count data (species richness). I have used
a linear model but the reviewers are recommending the use of negative binomial
or Poisson. As far as I could
Oi Joao,
From my understanding of the Poisson, as the Poisson mean (lambda) increases,
the distribution converges with the mean. I believe there are also issues
with the intercept since counts cannot be negative. If the variance is
excessive (var/df 1) then switch to negative binomial. So
