Dear all I am trying to estimate Kernels using the KernelUD in package adehabitatHR and I have some question regarding the argument GRID. I first run the function:
>Accgen.kernel<-kernelUD(Accgen_Sxy.laea, h = "href", grid = 100, > same4all = FALSE, > kern = c("bivnorm", "epa"), extent = 1, > boundary = NULL) And then I estimate the 50, 75 and 95% kernels, the centroids and the area of these polygons. >ver_Accgen <- getverticeshr(Accgen.kernel, 95, unout= "km2") ## 95 % >coordinates(ver_Accgen) > ## centroid >as.data.frame(ver_Accgen) ## area of the kernel So, first question: Which value of GRID is the most appropriate? Is there a rule of thumb to specify this value? second, why does the area of the kernel change when I change the value of GRID from 60 to 100? Shouldn't it be always the same? And if it shouldn't, which one should I take as "good"? Third, I have noticed that, for some species, when I try to calculate the 50% kernel, I get an error message ("out of bounds") which is dealt with by increasing the GRID value. So, if I want to compare results (e.g. area or centroid's location) between species, should I use the same grid value for all of them? Thank you so much for your time and help! Best Diego -- *Diego Pavón Jordán* *Finnish Museum of Natural History* *PO BOX 17 * *Helsinki. Finland* *0445061210https://tuhat.halvi.helsinki.fi/portal/en/persons/diego-pavon-jordan%288d5db37c-eddd-4fca-92cd-9c9956a42b4a%29.html <https://tuhat.halvi.helsinki.fi/portal/en/persons/diego-pavon-jordan%288d5db37c-eddd-4fca-92cd-9c9956a42b4a%29.html>http://www.linkedin.com/profile/view?id=170617924&trk=nav_responsive_tab_profile <http://www.linkedin.com/profile/view?id=170617924&trk=nav_responsive_tab_profile>https://helsinki.academia.edu/DiegoPavon <https://helsinki.academia.edu/DiegoPavon>* [[alternative HTML version deleted]] _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology