qp.devices.modifiers.simulator_tracking¶

simulator_tracking(cls)[source]¶

Modifies all methods to add default simulator style tracking.

Parameters:: cls (type) – a subclass of pennylane.devices.Device

Returns: type: The inputted class that has now been modified to update the tracker upon function calls.

Simulator style tracking updates:

executions: the number of unique circuits that would be required on quantum hardware
shots: the number of shots
resources: the Resources for the executed circuit.
"errors": combined algorithmic errors from the quantum operations executed by the qnode.
simulations: the number of simulations performed. One simulation can cover multiple QPU executions, such as for non-commuting measurements and batched parameters.
batches: The number of times execute() is called.
results: The results of each call of execute()
derivative_batches: How many times compute_derivatives() is called.
execute_and_derivative_batches: How many times execute_and_compute_derivatives() is called
vjp_batches: How many times compute_vjp() is called
execute_and_vjp_batches: How many times execute_and_compute_vjp() is called
jvp_batches: How many times compute_jvp() is called
execute_and_jvp_batches: How many times execute_and_compute_jvp() is called
derivatives: How many circuits are submitted to compute_derivatives() or execute_and_compute_derivatives().
vjps: How many circuits are submitted to pennylane.devices.Device.compute_vjp() or execute_and_compute_vjp()
jvps: How many circuits are submitted to compute_jvp() or execute_and_compute_jvp()

import pennylane as qp

from pennylane.devices.modifiers import simulator_tracking, single_tape_support

@simulator_tracking
@single_tape_support
class MyDevice(qp.devices.Device):

    def execute(self, circuits, execution_config: ExecutionConfig | None = None):
        return tuple(0.0 for c in circuits)

>>> dev = MyDevice()
>>> ops = [qp.S(0)]
>>> measurements = [qp.expval(qp.X(0)), qp.expval(qp.Z(0))]
>>> t = qp.tape.QuantumScript(ops, measurements,shots=50)
>>> with dev.tracker:
...     dev.execute((t, ) )
(0.0,)
>>> import pprint
>>> pprint.pprint(dev.tracker.history)
{'batches': [1],
 'errors': [{}],
 'executions': [2],
 'resources': [SpecsResources(gate_types={'S': 1},
                              gate_sizes={1: 1},
                              measurements={'expval(PauliX)': 1,
                                            'expval(PauliZ)': 1},
                              num_allocs=1,
                              depth=1)],
 'results': [0.0],
 'shots': [100],
 'simulations': [1]}

code/api/pennylane.devices.modifiers.simulator_tracking

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qp.devices.modifiers.simulator_tracking¶

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