qml.specs¶
-
specs(qnode, max_expansion=None, expansion_strategy=None)[source]¶ Resource information about a quantum circuit.
This transform converts a QNode into a callable that provides resource information about the circuit.
- Parameters
qnode (QNode) – the QNode to calculate the specifications for
- Keyword Arguments
max_expansion (int) – The number of times the internal circuit should be expanded when calculating the specification. Defaults to
qnode.max_expansion.expansion_strategy (str) –
The strategy to use when circuit expansions or decompositions are required.
gradient: The QNode will attempt to decompose the internal circuit such that all circuit operations are supported by the gradient method.device: The QNode will attempt to decompose the internal circuit such that all circuit operations are natively supported by the device.
- Returns
A function that has the same argument signature as
qnode. This function returns a dictionary of information about qnode structure.
Example
x = np.array([0.1, 0.2]) dev = qml.device('default.qubit', wires=2) @qml.qnode(dev, diff_method="parameter-shift", shifts=np.pi / 4) def circuit(x, add_ry=True): qml.RX(x[0], wires=0) qml.CNOT(wires=(0,1)) if add_ry: qml.RY(x[1], wires=1) return qml.probs(wires=(0,1))
>>> qml.specs(circuit)(x, add_ry=False) {'resources': Resources(num_wires=2, num_gates=2, gate_types=defaultdict(<class 'int'>, {'RX': 1, 'CNOT': 1}), gate_sizes=defaultdict(int, {1: 1, 2: 1}), depth=2, shots=Shots(total_shots=None, shot_vector=())), 'gate_sizes': defaultdict(int, {1: 1, 2: 1}), 'gate_types': defaultdict(int, {'RX': 1, 'CNOT': 1}), 'num_operations': 2, 'num_observables': 1, 'num_diagonalizing_gates': 0, 'num_used_wires': 2, 'num_trainable_params': 1, 'depth': 2, 'num_device_wires': 2, 'device_name': 'default.qubit', 'expansion_strategy': 'gradient', 'gradient_options': {'shifts': 0.7853981633974483}, 'interface': 'auto', 'diff_method': 'parameter-shift', 'gradient_fn': 'pennylane.gradients.parameter_shift.param_shift', 'num_gradient_executions': 2}