--- a/07-ls-filtration.py	Sat Jun 16 12:13:53 2012 -0700
+++ b/07-ls-filtration.py	Sat Jun 16 12:25:46 2012 -0700
@@ -4,13 +4,13 @@
 elephant_complex = closure(elephant_complex, 2)
 show_complex(elephant_points, elephant_complex)
 
-def axis(points, axis = 1):
+def projection(points, axis = 1):
     def value(v):
         return points[v][axis]
 
     return value
 
-value = axis(elephant_points, 1)
+value = projection(elephant_points, 1)
 
 
 def max_vertex_compare(values):

--- a/08-extended-persistence.py	Sat Jun 16 12:13:53 2012 -0700
+++ b/08-extended-persistence.py	Sat Jun 16 12:25:46 2012 -0700
@@ -2,12 +2,12 @@
 cone = [Simplex([-1] + [v for v in s.vertices]) for s in elephant_complex]
 cone.append(Simplex([-1]))
 
-def axis(points, axis = 1):
+def projection(points, axis = 1):
     def value(v):
         return points[v][axis]
 
     return value
-value = axis(elephant_points, 1)
+value = projection(elephant_points, 1)
 
 def ep_compare(values):
     def max_vertex(s):
@@ -17,13 +17,18 @@
         return min(values(v) for v in s.vertices if v != -1)
 
     def compare(s1, s2):
+        if s1.dimension() == 0 and -1 in s1.vertices:
+            return -1
+        if s2.dimension() == 0 and -1 in s2.vertices:
+            return 1
+
         if s1.dimension() != s2.dimension():
             return cmp(s1.dimension(), s2.dimension())
 
-        if (-1 in s1.vertices) ^ (-1 in s2.vertices):
+        if (-1 in s1.vertices) ^ (-1 in s2.vertices):       # only one cone simplex
             return 1 if -1 in s1.vertices else -1
         elif -1 in s1.vertices:
-            return cmp(min_vertex(s1), min_vertex(s2))
+            return -cmp(min_vertex(s1), min_vertex(s2))
         else:
             return cmp(max_vertex(s1), max_vertex(s2))
 
@@ -47,6 +52,6 @@
 
 dgms = init_diagrams(persistence, f, eval_ep(value), lambda i: i)
 
-show_diagram(dgms)
+print show_diagram(dgms)
 #print dgms
 #print len(dgms)