I have two routine tasks that I am wasting time over trying to solve. Can anyone help? I want to display the results of some geostatistical analysis quickly in R before exporting back to GIS . Does anyone have a trick for overlaying a polygon on an image of a krigging surface (prmat in spatial) in such a way that the space outside the polygon is whited out (so I trim within state boundaries)? Also, has anyone got a function for converting decimal degrees to UTM within R itself? Thanks, Duncan Golicher Departamento de Ecolog?a y Sistem?tica Terrestre El Colegio de la Frontera Sur Carretera Panamericana y Perif?rico Sur s/n C.P. 29290, San Crist?bal de Las Casas, Chiapas Tel. (967) 81883 y 81884, ext. 5115, Fax (967) 82322 Email: dgoliche at sclc.ecosur.mx Internet: http://www.ecosur.mx/bosques