plot(my.procrustes.model) from library {vegan}

Dear All,

I would like to ask how to customize the graph corresponding to a
procrustes analysis.

I have to distance matrices, that I transform to two set of coordinates
by means of muti dimensional scaling:

library(mva)

c1<-cmdscale(mat.dist1)
c2<-cmdscale(mat.dist2) 

I vant to rotate c2 on c1, and I use the "procrustes" analysis from the
{vegan} library.

library(vegan)

mod.pro<-procrustes(c1,c2)

plot(mod.pro)

My problem is that I need to change the graphical output of
plot(mod.pro). The standard output gives empty circles for the rotated
c2 matrix and arrows pointing to the target c1 matrix. 

I would like to have two set of symbols, one for c1 and the other for
c2, with a line connecting the corresponding points or at worst I would
like to have circles for the point of the target matix and the arrows
pointing to the rotated matrix.

I tried some manipulations based on the standard "plot" function, but I
was quite unsucessful. Can anyone give advice? I am happy to give a toy
example if needed.

Regards,

Federico Calboli

=================================

Federico C. F. Calboli

Dipartimento di Biologia
Via Selmi 3
40126 Bologna
Italy

tel (+39) 051 209 4187
fax (+39) 051 251 208

f.calboli at ucl.ac.uk