search for: kdot

...pattern of bird nests and each nest has a mark that it is either predated or not-predated. I want to test the null hypothesis that the K distribution of predation events is equal to the K distribution of all events (nests). This is the code I am using: Kdif <- function(X,...,i) { Kidot <- Kdot(X,...,i=i) K <- Kest(X,...) dif <- eval.fv(Kidot-K) return(dif) } E <- envelope(ppp, Kdif, nsim=100, i="Predated", simulate=expression(rlabel(ppp))) plot(E, main="clustering of predation events") I got this code from the 'Analazing spatial patterns in R Workshop n...

...Howeve, in the above 'markcorr' calculates G(m1,m2)=m1*m2 by default. So need to specify the test function to be G(m1,m2)= sin(abs(m1-m2))^2. According to the spatstat manual (p177), I may need to 'cook up' a specific function, like this: Kdif = function(X, ..., i) { Kidot = Kdot(X, ..., i = i) K = Kest(X, ...) dif = eval.fv(Kidot - K) return(dif) } E = envelope(lansing, Kdif, i='blackoak', simulate=expression(rlabel(lansing))) So how do I tell 'envelope' that I want to specify the mark correlation test function ?? Many thanks in advance! T...

Hi Is there anyone who can help a reporter (me) with the following: I want to use the bivirate k-function to determin if burgerbars are clustered around schools. To that purpose I’ve been told to use the bivirate k-function, but my program Arcview doesn’t contain that. Im stuck on a dead end – how to I for a start get the data into R? Michael Holm DICAR – Center for Anaytical Reporting