[AniMov] kernelUD error

Hazel, Julia julia.hazel at jcu.edu.au
Sat Mar 5 06:48:39 CET 2011


Dear all,

Many thanks to those who create and maintain AniMov software! 
After a steep learing curve with adehabitat I'm finding it very useful.
However with kernels for short periods, I sometimes get an error.
It seems this is caused by a set of locations that don't change.

### adehabitatHR_0.1  R 2.12.1 Windows XP
#demo: error with animal at same location during period of interest
X <- rep(699889, 10)
Y <- rep(3161559, 10)
Name <- rep("Brock", 10)
test <- data.frame (Name, X, Y)
coordinates(test) <- c("X", "Y") 
ud <- kernelUD(test)
#Error in points2grid(points, tolerance, round, fuzz.tol) : 
#  cannot determine cell size from constant coordinate 1

#demo: no error after small change in one location
XX <- c(rep(699889, 9), 699890)
YY <- c(rep(3161559, 9), 3161560)
Name <- rep("Brock", 10)
test2 <- data.frame (Name, XX, YY)
coordinates(test2) <- c("XX", "YY") 
ud2 <- kernelUD(test2)

Apologies in advance if this problem arises from newbie misunderstanding. However unchanging locations (over a limited time) are a valid occurrence in my data so I will be very grateful for the solution.

Thanks and best wishes,

Julia

Julia Hazel Ph.D.
Adjunct Research Fellow
School of Earth and Environmental Sciences
James Cook University, Townsville
QLD 4811
Phone: 0407 431 382 (international +61 407 431 382)
Email: Julia.Hazel at jcu.edu.au


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