Dear all,
I'm trying to create a distance matrix with my sampling design : I have two sampling areas, with 3 sites in each. In each site, I've 5 pitfall traps separated to 10 m from each others (so, N = 30 pitfall traps) (please, see the attached file which better explain this design).
I would like to calculate a connectivity matrix based on the MEM method (Moran’s eigenvector maps), connecting all of the pitfall traps to evaluate the effect of distance between the trap sets. I've the geographic coordinates of each site (centroids), BUT I don't have the coordinates of traps, necessary to take into account from the distance between each of them.
Is there a solution to create this sampling design with R including the distance beetween the traps in each of the six trap sets?
I hope that my question is clear...
Thanks a lot for your help!
William
Not sure I understand the problem. It seems that you have everything to place all the traps accurately with respect to each other, and to the centroid of each group. Get some graph paper; place the centroids where you say you know they should be. The traps are set relative to these -- assume the central trap in in each site is at the centroid of the area? What might be a slight unknown from your diagram is the vertical spacing of the rows of traps (also 10?)
If you can get the coordinates of everything, you can compute any function of the distance pair wise between every point.
I attach an excel example of how the points are laid out in a way that would allow distance calculations.
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