[R] conditioning variables in dbRDA

[Gavin Simpson]

On Mon, 2010-10-11 at 23:42 +1100, Nevil Amos wrote:
> I am using cascaple() in vegan, is it permissible to have more than 
> one conditioning variable thus
> capscale(DIST~varaible1+variable2+Conditon(varaible3+variable4), 
> data=mydata)

Yes. Have you tried it and had problems doing it? Or is this just a
request for clarification?

It does work:
> data(varespec)
> capscale(varespec ~ Ca + Condition(pH + P), varechem)
Call: capscale(formula = varespec ~ Ca + Condition(pH + P), data =
varechem)

              Inertia Rank
Total            1826     
Conditional       428    2
Constrained       130    1
Unconstrained    1268   20
Inertia is mean squared Euclidean distance 

Eigenvalues for constrained axes:
 CAP1 
130.0 

Eigenvalues for unconstrained axes:
  MDS1   MDS2   MDS3   MDS4   MDS5   MDS6   MDS7   MDS8 
739.77 226.54  89.04  70.61  36.72  30.47  24.77  18.64 
(Showed only 8 of all 20 unconstrained eigenvalues)

HTH

G

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