Dear List,

I am performing a spatial analysis for gridded data with ~8000 cells. Each
grid cell is 10 x 10 km and has one dependent and 4 independent variables.
The dependent variable is log-transformed and has some NAs. I generated a
first order queen neighbour object:

> vulcgrid.queen.nb

Neighbour list object:
Number of regions: 8281
Number of nonzero links: 64944
Percentage nonzero weights: 0.09470512
Average number of links: 7.842531

and then ran a Moran's I (after accounting for the missing values using
na.omit):

> lnemitpcap.morans.queen.1st

        Moran's I test under randomisation

data:  LNEMITPCAP
weights: vulcgrid.queen.nb.w
omitted: 7, 176, 259, 1304, 1424, 1473, 1532, 2101, 2273, 2436, 2451, 2884,
2921, 4260, 4271, 4454, 4577, 4957, 5111, 5126, 5589, 5837, 5871, 5994,
6084, 6315, 6527, 6528, 6696, 6697, 6865, 6946, 7022, 7034, 7115, 7558,
7638, 7658, 7780, 7898

Moran I statistic standard deviate = 58.0851, p-value < 2.2e-16
alternative hypothesis: greater
sample estimates:
Moran I statistic       Expectation          Variance
     3.249438e-01     -1.213592e-04      3.131927e-05

I wanted to test for the suitability of higher order neighbours and hence
tried sp.correlogram which does not work with NAs. Is there a workaround?
Also, on trying correlog() following suggestions in the ASDAR book, gives
the following output:

> vulcgrid.correlog <- correlog(coords, LNEMITPCAP, method = "Moran",
nbclass=NULL)
Error in correlog(coords, LNEMITPCAP, method = "Moran", nbclass = NULL) :
  Bad selection of class breaks, try another one...

How may I go about this? Do I need to manually specify distance bands? the
data are not on a regular grid. The GIS file is an extract from a larger
dataset for the conterminous US in North American Lambert Conformal Conic
projection with NAD 1983 datum. Suggestions are greatly appreciated.

Regards,

-- 
advait godbole

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