stacked graph attempt / 2

noblogsmv/webapp.py

@@ -35,7 +35,8 @@ def _mk_stacked_graph(chart, valuelist):
     v0 = [0] * n
     for j, values in enumerate(valuelist):
         for i, v in enumerate(values):
-            v0[i] += v
+            if v:
+                v0[i] += v
         chart.add_data(v0[:])
         chart.add_fill_range(_palette[i], j, j+1)
     chart.set_colours(['000000'] + _palette[:n])