Fix a bug in add_1q_gates (#251)

Author: BoxiLi

src/qutip_qip/circuit/circuit.py

@@ -273,11 +273,7 @@ def add_1q_gate(
         start=0,
         end=None,
         qubits=None,
-        arg_value=None,
-        arg_label=None,
-        classical_controls=None,
-        control_value=None,
-        classical_control_value=None,
+        **kwargs,
     ):
         """
         Adds a single qubit gate with specified parameters on a variable
@@ -287,45 +283,21 @@ def add_1q_gate(
         Parameters
         ----------
         name : string
-            Gate name.
+            Gate name or the :class:`~.operations.Gate` object.
         start : int
             Starting location of qubits.
         end : int
             Last qubit for the gate.
         qubits : list
             Specific qubits for applying gates.
-        arg_value : float
-            Argument value(phi).
-        arg_label : string
-            Label for gate representation.
+        kwargs : dict
+            Keyword arguments for the gate, except for `targets`.
+            See :class:`~.QubitCircuit.add_gate`.
         """
-        if qubits is not None:
-            for _, i in enumerate(qubits):
-                gate = GATE_CLASS_MAP[name](
-                    targets=qubits[i],
-                    controls=None,
-                    arg_value=arg_value,
-                    arg_label=arg_label,
-                    classical_controls=classical_controls,
-                    control_value=control_value,
-                    classical_control_value=classical_control_value,
-                )
-                self.gates.append(gate)
-
-        else:
-            if end is None:
-                end = self.N - 1
-            for i in range(start, end + 1):
-                gate = GATE_CLASS_MAP[name](
-                    targets=i,
-                    controls=None,
-                    arg_value=arg_value,
-                    arg_label=arg_label,
-                    classical_controls=classical_controls,
-                    control_value=control_value,
-                    classical_control_value=classical_control_value,
-                )
-                self.gates.append(gate)
+        if qubits is None:
+            qubits = range(start, end + 1)
+        for q in qubits:
+            self.add_gate(name, targets=q, **kwargs)
 
     def add_circuit(self, qc, start=0, overwrite_user_gates=False):
         """

tests/test_circuit.py

@@ -156,6 +156,7 @@ def test_add_gate(self):
         qc.add_gate("SNOT", targets=[3])
         qc.add_gate(test_gate, index=[3])
         qc.add_1q_gate("RY", start=4, end=5, arg_value=1.570796)
+        qc.add_1q_gate("RX", qubits=[3], arg_value=-1.570796)
 
         # Test explicit gate addition
         assert qc.gates[0].name == "CNOT"
@@ -176,7 +177,12 @@ def test_add_gate(self):
         assert qc.gates[5].arg_value == 1.570796
         assert qc.gates[6].name == "RY"
         assert qc.gates[6].targets == [5]
-        assert qc.gates[5].arg_value == 1.570796
+        assert qc.gates[6].arg_value == 1.570796
+
+        # Test adding 1 qubit gate on qubits [3] 
+        assert qc.gates[7].name == "RX"
+        assert qc.gates[7].targets == [3]
+        assert qc.gates[7].arg_value == -1.570796
 
         dummy_gate1 = Gate("DUMMY1")
         inds = [1, 3, 4, 6]
@@ -197,6 +203,7 @@ def test_add_gate(self):
             'RY',       # 8
             'DUMMY1',   # 9
             'RY',       # 10
+            'RX',       # 11
         ]
         actual_gate_names = [gate.name for gate in qc.gates]
         assert actual_gate_names == expected_gate_names
@@ -220,6 +227,7 @@ def test_add_gate(self):
             'DUMMY1',   # 10
             'RY',       # 11
             'DUMMY2',   # 12
+            'RX',       # 13
         ]
         actual_gate_names = [gate.name for gate in qc.gates]
         assert actual_gate_names == expected_gate_names