function err = g_error_polyfit(cv,lonlon,latlat,err_ll,order); n_gcp = length(err_ll); err = 0; for k = 1:n_gcp if order == 1 efit = cv(1)*lonlon(k)+cv(2)*latlat(k)+cv(3); elseif order == 2 efit = cv(1)*lonlon(k)^2+cv(2)*latlat(k)^2+cv(3)*lonlon(k)*latlat(k)+cv(4)*lonlon(k)+cv(5)*latlat(k)+cv(6); end err = err + (efit-err_ll(k))^2; end