esttheta: Numerically estimate theta parameter for rspUD
In jedalong/wildlifeTG: Time Geograhic Analysis of Wildlife Telemetry Data

Estimate theta parameter using leave-one-out estimation procedure for randomized shortest path utilization distributions.

1 2	esttheta(traj, r, rangetheta = c(0, 1), rand = NA, niter = 10, tolerance = 0.01, dmin = NA, dmax = NA, plot = TRUE)

`traj`	animal movement trajectory in the form of an `ltraj` object, see package `adehabitatLT`
`r`	a `RasterLayer` object describing the preference/permeability of the landscape. May be the result of a resource selection function, or other analyses. Note: Higher values should be associated higher preference or permeability.
`rangetheta`	uppper and lower bound for `theta` testing range (default = [0,1]).
`rand`	if `NA` (the default) every second segment is evauluated (n/2), otherwise an integer indicating how many random segments to test.
`niter`	used to define maximum number of iterations of golden-search routine
`tolerance`	used to define precision of golden search routine (i.e., routine stops when the absolute difference between two consecutive test points is below this value).
`dmin`	Use only segments where the movement distance is greater than dmin (default is NA or all segments).
`dmax`	Use only segments where the movement distance is less than dmax (default is NA or all segments).
`plot`	logical, whether or not to plot the likelihood curve.