Dear Zhifeng,
You have already sent me three personal emails about this, and I've already
responded that you should try with calc.FRic = FALSE. What is likely
happening is that R struggles to compute the multidimensional convex hull
volume with your data -- this is explained in ?dbFD. Why don't yo
Hi Zhifeng,
We need rather more information to help here. At least, your OS, version of
R, version of FD - sessionInfo() will provide much of it.
What are the dimensions of your data frame?
What is the output of str() for your data frame?
When you say "crashed," what exactly happened? Did you re
Dear list,
I am a beginner in R. Now I conduct my research in the Thousand Island
Lake, China, 50-year isolated islands in a man-made lake, to study the
impacts of habitat fragmentation on bird functional diversity (FRic, FEve,
FDiv and FDis).
But I faced some problems. I couldnt calculate
Chris,
This is an example of a study with 2 factors that is much easier to analyze as
a 1 way ANOVA. You have three treatments. The structure of those treatments
implies two interesting treatment contrasts:
the effect of raking, estimated by the difference between control and
procedural con
Hi Gavin Simpson, Thank you to bring this correction. Sorry for this mistake!
Momadou
De : Gavin Simpson
À : momadou sow
Cc : Christopher Cesar ; "R-sig-ecology@r-project.org"
Envoyé le : Mercredi 24 Août 2011 14h30
Objet : Re: [R-sig-eco] Re : guidance required (GLM?)
On Wed, 2011-08-24 a
On Wed, 2011-08-24 at 11:16 +0100, momadou sow wrote:
> Hi,
> With glm, you add the binomial family:
In general, no you don't - a GLM is far more than a logistic regression.
Otherwise, why would glm() allow for more families than just binomial?
As biomass is positive (or at least non-negative) an
Chris is unlikely to need a binomial model if the response variable is biomass.
glm is generalised linear model: are you sure you don't just want lm (linear
model with normal residuals) Chris?
You're new to stats, but you are trying to do something quite complex, you do
need to build up you kn
Hi,
With glm, you add the binomial family:
model<-glm(biomass~Shore*Raked*Species+Shore*Fished*Species,family=binomial)
model
De : Christopher Cesar
À : "r-sig-ecology@r-project.org"
Envoyé le : Mercredi 24 Août 2011 12h02
Objet : [R-sig-eco] guidance required (GLM?)
Hi all,
I have carried ou
Hi all,
I have carried out experimental removal of bivalves at 2 intertidal shores.
Bivalves were removed by raking of surface sediments. I wish compare the
biomass values of for a total of 8 species between the 2 shores
My 3 treatments are: Undisturbed Controls (Cont), Procedural Controls (Pro
