FixedPoint

class qiskit.transpiler.passes.FixedPoint(*args, **kwargs)

Bases: AnalysisPass

Check if a property reached a fixed point.

A dummy analysis pass that checks if a property reached a fixed point. The result is saved in property_set['<property_to_check>_fixed_point'] as a boolean.

An optional getter callable can be provided to derive a value from the property set instead of reading a single key directly. This is useful when convergence should be checked on a combination of properties (e.g. a tuple consisting of size and t-count):

def get_size_and_t_count(property_set):
    return (
        property_set["size"],
        property_set["count_ops"].get("t", 0) + property_set["count_ops"].get("tdg", 0)
    )

FixedPoint("size_and_t_count", get_size_and_t_count)

Parameters

property_to_check – The name used to key the fixed-point result in the property set under property_set['<property_to_check>_fixed_point']. When getter is None, this name is also used as a key to read the corresponding value from the property set.
getter – Optional callable that takes the property set as input and returns the value to track. When None (default), the value property_set[property_to_check] is used for tracking purposes.

Attributes

is_analysis_pass

Check if the pass is an analysis pass.

If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.

is_transformation_pass

Check if the pass is a transformation pass.

If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).

Methods

execute

execute(passmanager_ir, state, callback=None)

GitHub

Execute optimization task for input Qiskit IR.

Parameters

passmanager_ir (IR) – Qiskit IR to optimize.
state (PassManagerState) – State associated with workflow execution by the pass manager itself.
callback (Callable[[Task, IR_OUT, PropertySet, float, int], None] | None) – A callback function which is called per execution of optimization task.