diff --git a/engine/polygon.py b/engine/polygon.py
index <HASH>..<HASH> 100644
--- a/engine/polygon.py
+++ b/engine/polygon.py
@@ -459,7 +459,11 @@ class Polygon_function:
         else:
             z = [self.default] * N  # FIXME (Ole): Use NAN
 
+        k = 0
         for polygon, value in self.regions:
+            print ('Doing polygon %i of %i: L = %i'
+                   % (k, len(self.regions), len(polygon)))
+            k += 1
             indices = inside_polygon(points, polygon)
 
             if callable(value):
diff --git a/storage/vector.py b/storage/vector.py
index <HASH>..<HASH> 100644
--- a/storage/vector.py
+++ b/storage/vector.py
@@ -748,7 +748,7 @@ class Vector:
         N = len(X)
         assert len(atts) == N
 
-        print 'Interpolating'
+        print 'Interpolating %i points and %i polygons' %(N, len(regions))
         z = P(points[:, 0], points[:, 1])
         print 'Done z'
 
@@ -759,7 +759,9 @@ class Vector:
         data = X.get_data()
         if attribute is None:
             for i in range(N):
-                for attribute in z:
+                print i, z[i]
+                print z[i].keys()
+                for attribute in z[i]:
                     # FIXME(Ole): What if there is a name clash?
                     data[i][attribute] = {attribute: z[i][attribute]}
         else:
Calling it a night - added some debugging print statements