Fitting Function for Spatial Linear Models

USAGE:

slm.fit(x, y, cov.family, initial, spatial.arglist, ...) 
This function is included to be consistent with the lm routines. It performs a few assignments for the slm routine, but these are not critical. See function slm for additional information. For most purposes, you would be better off calling the lower-level function directly unless you want to write code that takes the method argument.