spatial correlation test
On Monday 30 June 2003 15:23, Barry Rowlingson wrote:
Think you may be looking at the wrong sort of spatial correlation! For Geary tests you are comparing 'adjacent' objects, where adjacency is defined however you want - N-nearest neighbours, shared border between regions etc etc.
sorry, I misunderstood the purpose of geary's I test, thanks for this info.
When you say 'sampled data' it sounds more like you've got samples taken at locations, and you want to investigate spatial correlation as a function of distance between samples? Am I guessing right?
Yes you are right. I want to look for spatial correlation of my samples as a function of distances between sampling sites (x,y coords).
Take a look at some of the R kriging libraries, which will have functions to plot variograms. This is a plot of something like E(|Y_i - Y_j|) against distance. Baz
I found variograms() and correlograms(), but is there a way to get the a p-value for spatial correlation? additionaly I found sp.correlogram() but again with this mysterious "nb class". thanks, martin