stata操作GWR模型

在用stata中跑GWR模型，里面的east和north是什么意思诶？求大神指教~
gwr k log_landfees tpop gdp,east(varname)north(varname)reps(1000)dots test saving(gwrout)replace nolog

east(varname)  should specify the name of the variable denoting the easting
of each point in space.

north(varname) should specify the name of the variable denoting the  
northing of each point in space.
应该就是东经和北纬的意思吧