-------- GM spatial estimation functions -------- 

 
dbffile_read   : reads an arcview (or other) dbffile and returns a structure containing
dbffile_readd  : An example of using dbf_read() cmex function
make_map       : constucts a map using structure variable returned by read_shape()
map_demo       : An example of using shape_read() and make_map()
shape_read     : reads an arcview shapfile and returns a structure 
shape_readd    : An example of using shape_read()