Hella tidy

local_cliffords.py

@@ -11,8 +11,29 @@ Following the prescription of Anders (thesis pg. 26):
 > indicated by the column header and the opposite sign otherwise.
 """ 
 
+# TODO:
+# - check that we re-generate the table
+# - sort of re-map to an ordering 
+# - do conjugation
+# - do times table
+# - write tests
+
 from numpy import *
 
+def identify_pauli(m):
+    """ Given a signed Pauli matrix, name it. """
+    for sign in (+1, -1):
+        for pauli_label, pauli in zip("xyz", paulis):
+            if allclose(sign*pauli, m):
+                return sign, pauli_label
+
+def anders_sign_rule(sign, column, p):
+    """ Anders' sign rule from thesis """
+    return sign if (p==column or column=="i") else -sign, p
+
+def format_action(action):
+    return "".join("{}{}".format("+" if s>=0 else "-", p) for s, p in action)
+
 # Some two-qubit matrices
 i = matrix(eye(2, dtype=complex))
 px = matrix([[0, 1], [1, 0]], dtype=complex)
@@ -28,47 +49,18 @@ s_names = ["i", "p", "pp", "ppp"]
 c_rotations = [i, h, h*p, h*p*p, h*p*p*p, h*p*p*h]
 c_names = ["i", "h", "hp", "hpp", "hppp", "hpph"]
 
-def get_sign(x):
-    """ Get the sign of a number """
-    return "+" if x>=0 else "-"
-
-def identify_pauli(m):
-    """ Given a signed Pauli matrix, name it. """
-    for sign_label, sign in (("+", +1), ("-", -1)):
-        for pauli_label, pauli in zip("xyz", paulis):
-            if allclose(sign*pauli, m):
-                return "{}{}".format(sign_label, pauli_label)
-
-def get_action(u):
-    """ Get the action of a Pauli matrix on three qubits """
-    return tuple(identify_pauli(u*p*u.H) for p in paulis)
-
-def cliff_action(permutation, op):
-    """ Computes the action of a particular local Clifford """
-
-
-if __name__ == '__main__':
-    labels =       ("a"   , "b"   , "c"   , "d"   , "e"   , "f")
-    signs =        (+1    , -1    , -1    , -1    , +1    , +1)
-    permutations = ("xyz" , "yxz" , "zyx" , "xzy" , "yzx" , "zxy")
-    anders = {}
-    anders_inv = {}
-
-    for label, sign, permutation in zip(labels, signs, permutations):
-        for op in "ixyz":
-            signs = [sign if (a == op or op == "i") else -sign for a in "xyz"]
-            effect = "".join("{}{}".format(get_sign(x), y) 
-                    for x, y in zip(signs, permutation))
-            anders["{}{}".format(op, label)] = effect
-            anders_inv[effect] = "{}{}".format(op, label)
-
-    print anders
-    print anders_inv
-
+# Build the table of VOPs according to Anders (verbatim from thesis)
+table = (("a", "xyz", +1), ("b", "yxz", -1), ("c", "zyx", -1),
+          ("d", "xzy", -1), ("e", "yxz", +1), ("f", "zxy", +1))
 
-    for s, sn in zip(s_rotations, s_names):
-        for c, cn in zip(c_rotations, c_names):
-            action = "".join(get_action(s*c))
-            print anders_inv[action]
+for label, permutation, sign in table:
+    for column, operator in zip("ixyz", "i"+permutation):
+        effect = [anders_sign_rule(sign, column, p) for p in "xyz"]
+        print label+operator, format_action(effect)
 
+for s, sn in zip(s_rotations, s_names):
+    for c, cn in zip(c_rotations, c_names):
+        u = s*c
+        action = tuple(identify_pauli(u*p*u.H) for p in paulis)
+        print cn, sn, format_action(action)
 

tests/test_local_cliffords.py

@@ -7,3 +7,7 @@ def test_identify_pauli():
 
 def test_get_action():
     assert lc.get_action(lc.i) == ("+x", "+y", "+z")
+
+def test_crap():
+    lc.vops[0]
+