def pysal_Gamma(self, **kwargs):
if self.weights is None:<EOL><INDENT>self.raster_weights(**kwargs)<EOL><DEDENT>rasterf = self.raster.flatten()<EOL>rasterf = rasterf[rasterf.mask==False]<EOL>self.Gamma = pysal.Gamma(rasterf, self.weights, **kwargs)<EOL>
Compute Gamma Index of Spatial Autocorrelation for GeoRaster

Usage:
geo.pysal_Gamma(permutations = 1000, rook=True, operation='c')

arguments passed to raster_weights() and pysal.Gamma
See help(gr.raster_weights), help(pysal.Gamma) for options