Change BasicGate __eq__ to test for matrix attribute (ProjectQ-Framework#252)

damiansteiger · web-flow · commit 4674e11baa58 · 2018-08-07T14:30:13.000+02:00
diff --git a/projectq/backends/_sim/_simulator_test.py b/projectq/backends/_sim/_simulator_test.py
@@ -147,15 +147,15 @@ def test_simulator_is_available(sim):
 
     new_cmd.gate = Mock1QubitGate()
     assert sim.is_available(new_cmd)
-    assert new_cmd.gate.cnt == 1
+    assert new_cmd.gate.cnt == 4
 
     new_cmd.gate = Mock6QubitGate()
     assert not sim.is_available(new_cmd)
-    assert new_cmd.gate.cnt == 1
+    assert new_cmd.gate.cnt == 4
 
     new_cmd.gate = MockNoMatrixGate()
     assert not sim.is_available(new_cmd)
-    assert new_cmd.gate.cnt == 1
+    assert new_cmd.gate.cnt == 7
 
 
 def test_simulator_cheat(sim):
diff --git a/projectq/cengines/_replacer/_replacer_test.py b/projectq/cengines/_replacer/_replacer_test.py
@@ -178,8 +178,6 @@ def magic_filter(self, cmd):
     qb = eng.allocate_qubit()
     MagicGate() | qb
     eng.flush()
-    for cmd in backend.received_commands:
-        print(cmd)
     assert len(backend.received_commands) == 4
     assert backend.received_commands[1].gate == H
     assert backend.received_commands[2].gate == Rx(-0.6)
diff --git a/projectq/ops/_basics.py b/projectq/ops/_basics.py
@@ -34,12 +34,16 @@
 import math
 from copy import deepcopy
 
+import numpy as np
+
 from projectq.types import BasicQubit
 from ._command import Command, apply_command
 
 
 ANGLE_PRECISION = 12
 ANGLE_TOLERANCE = 10 ** -ANGLE_PRECISION
+RTOL = 1e-10
+ATOL = 1e-12
 
 
 class NotMergeable(Exception):
@@ -200,8 +204,39 @@ def __or__(self, qubits):
         apply_command(cmd)
 
     def __eq__(self, other):
-        """ Return True if equal (i.e., instance of same class). """
-        return isinstance(other, self.__class__)
+        """ Return True if equal (i.e., instance of same class).
+
+            Unless both have a matrix attribute in which case we also check
+            that the matrices are identical as people might want to do the
+            following:
+
+            Example:
+                .. code-block:: python
+
+                gate = BasicGate()
+                gate.matrix = numpy.matrix([[1,0],[0, -1]])
+        """
+        if hasattr(self, 'matrix'):
+            if not hasattr(other, 'matrix'):
+                return False
+        if hasattr(other, 'matrix'):
+            if not hasattr(self, 'matrix'):
+                return False
+        if hasattr(self, 'matrix') and hasattr(other, 'matrix'):
+            if (not isinstance(self.matrix, np.matrix) or
+                    not isinstance(other.matrix, np.matrix)):
+                raise TypeError("One of the gates doesn't have the correct "
+                                "type (numpy.matrix) for the matrix "
+                                "attribute.")
+            if (self.matrix.shape == other.matrix.shape and
+                np.allclose(self.matrix, other.matrix,
+                            rtol=RTOL, atol=ATOL,
+                            equal_nan=False)):
+                return True
+            else:
+                return False
+        else:
+            return isinstance(other, self.__class__)
 
     def __ne__(self, other):
         return not self.__eq__(other)
diff --git a/projectq/ops/_basics_test.py b/projectq/ops/_basics_test.py
@@ -14,10 +14,12 @@
 
 """Tests for projectq.ops._basics."""
 
-import pytest
 from copy import deepcopy
 import math
 
+import numpy as np
+import pytest
+
 from projectq.types import Qubit, Qureg
 from projectq.ops import Command
 from projectq import MainEngine
@@ -116,6 +118,13 @@ def test_basic_gate_compare():
     gate2 = _basics.BasicGate()
     assert gate1 == gate2
     assert not (gate1 != gate2)
+    gate3 = _basics.BasicGate()
+    gate3.matrix = np.matrix([[1, 0], [0, -1]])
+    assert gate1 != gate3
+    gate4 = _basics.BasicGate()
+    gate4.matrix = [[1, 0], [0, -1]]
+    with pytest.raises(TypeError):
+        gate4 == gate3
 
 
 def test_comparing_different_gates():
diff --git a/projectq/ops/_qftgate.py b/projectq/ops/_qftgate.py
@@ -22,5 +22,6 @@ class QFTGate(BasicGate):
     def __str__(self):
         return "QFT"
 
+
 #: Shortcut (instance of) :class:`projectq.ops.QFTGate`
 QFT = QFTGate()
diff --git a/projectq/ops/_qftgate_test.py b/projectq/ops/_qftgate_test.py
@@ -20,3 +20,7 @@
 def test_qft_gate_str():
     gate = _qftgate.QFT
     assert str(gate) == "QFT"
+
+
+def test_qft_equality():
+    assert _qftgate.QFT == _qftgate.QFTGate()
diff --git a/projectq/setups/decompositions/carb1qubit2cnotrzandry_test.py b/projectq/setups/decompositions/carb1qubit2cnotrzandry_test.py
@@ -58,8 +58,8 @@ def test_recognize_incorrect_gates():
         BasicGate() | qubit
         # Two qubit gate:
         two_qubit_gate = BasicGate()
-        two_qubit_gate.matrix = [[1, 0, 0, 0], [0, 1, 0, 0],
-                                 [0, 0, 1, 0], [0, 0, 0, 1]]
+        two_qubit_gate.matrix = np.matrix([[1, 0, 0, 0], [0, 1, 0, 0],
+                                           [0, 0, 1, 0], [0, 0, 0, 1]])
         two_qubit_gate | qubit
     with Control(eng, ctrl_qureg):
         # Too many Control qubits:
