fixes to demlw, now always returns a uint8 and does some basic value checking

demlw/demlw.py

@@ -102,19 +102,22 @@ class DemLW(object):
   
   def latlon2demlw(self, longitudes, latitudes):
   
-#    # First fill in with 30 arc sec data
-#    lw = self._map_subgrids(longitudes, latitudes, self.DEM_30_DICT)
-#  
-#    # Get a mask of the fill values
-#    fills = (lw == 221)
-#  
-#    # Now replace those fill values with values from 30 arc file
-#    lw[fills] = self._map_subgrids(longitudes[fills], latitudes[fills], self.DEM_15_DICT)
-
-    # FIXME: fills seem to have changed, just use ARC15 for now as speedup seems negligable
+    # First fill in with 30 arc sec data
     lw = self._map_subgrids(longitudes, latitudes, self.DEM_15_DICT)
+  
+    # Get a mask of the fill values
+    fills = (lw == 221)
+  
+    # Now replace those fill values with values from 30 arc file
+    lw[fills] = self._map_subgrids(longitudes[fills], latitudes[fills], self.DEM_30_DICT)
 
-    return lw
+    if np.any(lw > 8):
+      raise RuntimeError, "Invalid LW value (>8)"
+
+    if np.any(lw < 0):
+      raise RuntimeError, "Invalid LW value (<0)"
+
+    return lw.astype(np.uint8)