Join count analysis in R

Hi,

I am trying to do some join count statistical analysis on my data (a
grid of 5000 cells with values 1 or 0) in order to determine whether
there is spatial clustering of pixels. Is there a built-in function
available in any of the spatial stats packages of R (I cannot seem to
locate it, if it is present)?

Geetha

On Wed, 25 May 2011, geetha ramaswami wrote:

Hi,

I am trying to do some join count statistical analysis on my data (a
grid of 5000 cells with values 1 or 0) in order to determine whether
there is spatial clustering of pixels. Is there a built-in function
available in any of the spatial stats packages of R (I cannot seem to
locate it, if it is present)?

See joincoint.test() in spdep for the original Cliff/Ord test. You'll need
to construct a weights object, probably using dnearneigh() and nb2listw() in
the same package, and ensure that the input data are in vector form in the
same order as the weights. See also the examples for joincoint.test() and
joincoint.multi().

Roger

Geetha

--
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no