Remove some unsupported 2-qubit gates and implement minor fixes

Author: SimoneGasperini

src/qiskit_symb/circuit/__init__.py

@@ -51,20 +51,16 @@
     'rxx': RXXGate,
     'ryy': RYYGate,
     'rzz': RZZGate,
-    'rzx': RZXGate,
-    'xx_minus_yy': XXMinusYYGate,
-    'xx_plus_yy': XXPlusYYGate,
 }
 
 
+def get_gates():
+    """todo"""
+    return set(name2class.keys())
+
+
 def get_class(op):
     """todo"""
-    if isinstance(op, ControlledGate):
-        name = 'c' + op.base_gate.name
-    else:
-        name = op.name
-    try:
-        return name2class[name]
-    except KeyError as kerr:
-        error_message = f'Gate "{name}" is not implemented in qiskit-symb'
-        raise NotImplementedError(error_message) from kerr
+    is_controlled = isinstance(op, ControlledGate)
+    name = 'c' + op.base_gate.name if is_controlled else op.name
+    return name2class[name]

src/qiskit_symb/circuit/library/__init__.py

@@ -28,7 +28,4 @@
     RXXGate,
     RYYGate,
     RZZGate,
-    RZXGate,
-    XXMinusYYGate,
-    XXPlusYYGate,
 )

src/qiskit_symb/circuit/library/parametric_gates/__init__.py

@@ -12,6 +12,3 @@
 from .rxx import RXXGate
 from .ryy import RYYGate
 from .rzz import RZZGate
-from .rzx import RZXGate
-from .xx_minus_yy import XXMinusYYGate
-from .xx_plus_yy import XXPlusYYGate

src/qiskit_symb/circuit/library/parametric_gates/rzx.py

@@ -4,7 +4,7 @@
 from qiskit.circuit.random import random_circuit
 
 
-def random_parametric_circuit(num_qubits, depth, max_operands=2, seed=None):
+def random_parametric_circuit(num_qubits, depth, max_operands=3, seed=None):
     """todo"""
     random_qc = random_circuit(
         num_qubits=num_qubits, depth=depth, max_operands=max_operands, seed=seed)

src/qiskit_symb/circuit/library/parametric_gates/xx_minus_yy.py

@@ -40,10 +40,13 @@ def __init__(self, data, nqubits=None, params=None):
     @staticmethod
     def _get_sympy_expr(circuit):
         """todo"""
+        from ..circuit import get_gates
         from ..circuit.gate import Gate
         num_qubits = circuit.num_qubits
         circuit = QuantumCircuit(num_qubits).compose(circuit)
-        circuit = transpile(circuit, optimization_level=1)
+        basis_gates = get_gates()
+        circuit = transpile(
+            circuit, basis_gates=basis_gates, optimization_level=1)
         zero = [1] + [0] * (2**num_qubits - 1)
         state_tensor = sympy.Array(zero, shape=(2,)*num_qubits)
         for layer in circuit_to_dag(circuit).layers():
@@ -53,9 +56,8 @@ def _get_sympy_expr(circuit):
             gates_tensors = [gate._get_tensor_array() for gate in gates]
             state_tensor = opt_einsum.contract(
                 einsum_contract, state_tensor, *gates_tensors)
-            print(sympy.flatten(state_tensor))
         gph = sympy.exp(sympy.I * circuit.global_phase)
-        state_tensor = gph * sympy.Array(state_tensor, shape=(2**num_qubits))
+        state_tensor = gph * sympy.Array(state_tensor, shape=2**num_qubits)
         return state_tensor
 
     @classmethod
@@ -79,16 +81,20 @@ def to_numpy(self):
         """todo"""
         return numpy.array(self.to_sympy().tolist(), dtype=complex)
 
-    def to_lambda(self):
+    def _lambdify(self, sympy_expr):
         """todo"""
-        sympy_expr = self.to_sympy()
         name2symb = {symb.name: symb for symb in sympy_expr.free_symbols}
         args = [name2symb[par.name]
                 if par.name in name2symb
                 else sympy.Symbol('_')
                 for par in self._params]
         return sympy.lambdify(args=args, expr=sympy_expr, modules='numpy', dummify=True, cse=True)
 
+    def to_lambda(self):
+        """todo"""
+        sympy_expr = self.to_sympy()
+        return self._lambdify(sympy_expr=sympy_expr)
+
     def subs(self, params_dict):
         """todo"""
         par2val = {}

src/qiskit_symb/circuit/library/parametric_gates/xx_plus_yy.py

@@ -28,6 +28,7 @@
 
 
 def convert_endian(unitary):
+    """todo"""
     nq = int(numpy.log2(len(unitary)))
     perm = [int(bin(i)[2:].zfill(nq)[::-1], 2) for i in range(len(unitary))]
     return unitary[numpy.ix_(perm, perm)]

src/qiskit_symb/circuit/random.py

@@ -28,6 +28,7 @@
 
 
 def convert_endian(unitary):
+    """todo"""
     nq = int(numpy.log2(len(unitary)))
     perm = [int(bin(i)[2:].zfill(nq)[::-1], 2) for i in range(len(unitary))]
     return unitary[numpy.ix_(perm, perm)]

src/qiskit_symb/quantum_info/statevector.py

@@ -16,9 +16,6 @@
     RXXGate,
     RYYGate,
     RZZGate,
-    RZXGate,
-    XXMinusYYGate,
-    XXPlusYYGate,
 )
 from qiskit_symb.circuit.library import (
     UGate as symb_UGate,
@@ -33,9 +30,6 @@
     RXXGate as symb_RXXGate,
     RYYGate as symb_RYYGate,
     RZZGate as symb_RZZGate,
-    RZXGate as symb_RZXGate,
-    XXMinusYYGate as symb_XXMinusYYGate,
-    XXPlusYYGate as symb_XXPlusYYGate,
 )
 
 val_range = {'min_value': -2*numpy.pi, 'max_value': 2*numpy.pi}
@@ -169,37 +163,3 @@ def test_rzz(theta):
     gate = symb_RZZGate(par, 0, 1)
     arr2 = gate.get_numpy_repr(par2val={par: theta})
     assert numpy.allclose(arr1, arr2)
-
-
-@given(theta=strategies.floats(**val_range))
-def test_rzx(theta):
-    """todo"""
-    par = Parameter(name='par')
-    arr1 = RZXGate(theta).to_matrix()
-    gate = symb_RZXGate(par, 0, 1)
-    arr2 = gate.get_numpy_repr(par2val={par: theta})
-    assert numpy.allclose(arr1, arr2)
-
-
-@given(theta=strategies.floats(**val_range),
-       beta=strategies.floats(**val_range))
-def test_xx_minus_yy(theta, beta):
-    """todo"""
-    pars_vals = [theta, beta]
-    pars = ParameterVector(name='pars', length=len(pars_vals))
-    arr1 = XXMinusYYGate(*pars_vals).to_matrix()
-    gate = symb_XXMinusYYGate(*pars, 0, 1)
-    arr2 = gate.get_numpy_repr(par2val=dict(zip(pars, pars_vals)))
-    assert numpy.allclose(arr1, arr2)
-
-
-@given(theta=strategies.floats(**val_range),
-       beta=strategies.floats(**val_range))
-def test_xx_plus_yy(theta, beta):
-    """todo"""
-    pars_vals = [theta, beta]
-    pars = ParameterVector(name='pars', length=len(pars_vals))
-    arr1 = XXPlusYYGate(*pars_vals).to_matrix()
-    gate = symb_XXPlusYYGate(*pars, 0, 1)
-    arr2 = gate.get_numpy_repr(par2val=dict(zip(pars, pars_vals)))
-    assert numpy.allclose(arr1, arr2)

tests/test_ctrl_parametric_gates.py

@@ -38,6 +38,7 @@
 
 
 def convert_endian(unitary):
+    """todo"""
     nq = int(numpy.log2(len(unitary)))
     perm = [int(bin(i)[2:].zfill(nq)[::-1], 2) for i in range(len(unitary))]
     return unitary[numpy.ix_(perm, perm)]