DiggleGratton {spatstat} | R Documentation |
Creates an instance of the Diggle-Gratton pairwise interaction point process model, which can then be fitted to point pattern data.
DiggleGratton(delta, rho)
delta |
lower threshold delta |
rho |
upper threshold rho |
Diggle and Gratton (1984, pages 208-210) introduced the pairwise interaction point process with pair potential h(t) of the form
h(t) = ((t - delta)/(rho - delta))^beta, { } delta <= t <= rho
with h(t) = 0 for t < delta and h(t) = 1 for t > rho.
Here delta <= rho are irregular parameters. The potential is inhibitory, i.e. this model is only appropriate for regular point patterns.
Note that the irregular parameters delta, rho must be fixed, while the regular parameter beta will be estimated.
An object of class "interact"
describing the interpoint interaction
structure of a point process.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
Diggle, P.J. and Gratton, R.J. (1984) Monte Carlo methods of inference for implicit statistical models. Journal of the Royal Statistical Society, series B 46, 193 212.
data(cells) mpl(cells, ~1, DiggleGratton(0.05, 0.1)) # NOTE: resulting estimate of beta is 8.569, not exp(8.569) = 5267.54