from dionysus import Simplex, ZigzagPersistence, \

                      vertex_cmp, data_cmp \

 #                    ,enable_log

 complex = {Simplex((0,),        0):     None,                   # A

            Simplex((1,),        1):     None,                   # B

            Simplex((2,),        2):     None,                   # C

            Simplex((0,1),       2.5):   None,                   # AB

            Simplex((1,2),       2.9):   None,                   # BC

            Simplex((0,2),       3.5):   None,                   # CA

            Simplex((0,1,2),     5):     None}                   # ABC

 print "Complex:"

 for s in sorted(complex.keys()): print s

 print

 #enable_log("topology/persistence")

 zz = ZigzagPersistence()

 # Add all the simplices

 b = 1

 for s in sorted(complex.keys(), data_cmp):

     print "%d: Adding %s" % (b, s)

     i,d = zz.add([complex[ss] for ss in s.boundary], b)

     complex[s] = i

     if d:   print "Interval (%d, %d)" % (d, b-1)

     b += 1

 # Remove all the simplices

 for s in sorted(complex.keys(), data_cmp, reverse = True):

     print "%d: Removing %s" % (b, s)

     d = zz.remove(complex[s], b)

     del complex[s]

     if d:   print "Interval (%d, %d)" % (d, b-1)

     b += 1