EquivalenceLibrary
class qiskit.circuit.EquivalenceLibrary(*, base=None)
Bases: object
A library providing a one-way mapping of Gates to their equivalent implementations as QuantumCircuits.
Create a new equivalence library.
Parameters
base (Optional[EquivalenceLibrary]) – Base equivalence library to be referenced if an entry is not found in this library.
Attributes
graph
Return graph representing the equivalence library data.
This property should be treated as read-only as it provides a reference to the internal state of the EquivalenceLibrary object. If the graph returned by this property is mutated it could corrupt the the contents of the object. If you need to modify the output PyDiGraph be sure to make a copy prior to any modification.
Returns
A graph object with equivalence data in each node.
Return type
PyDiGraph
Methods
add_equivalence
add_equivalence(gate, equivalent_circuit)
Add a new equivalence to the library. Future queries for the Gate will include the given circuit, in addition to all existing equivalences (including those from base).
Parameterized Gates (those including qiskit.circuit.Parameters in their Gate.params) can be marked equivalent to parameterized circuits, provided the parameters match.
Parameters
- gate (Gate) – A Gate instance.
- equivalent_circuit (QuantumCircuit) – A circuit equivalently implementing the given Gate.
draw
draw(filename=None)
Draws the equivalence relations available in the library.
Parameters
filename (str) – An optional path to write the output image to if specified this method will return None.
Returns
Drawn equivalence library as an
IPython SVG if in a jupyter notebook, or as a PIL.Image otherwise.
Return type
PIL.Image or IPython.display.SVG
Raises
InvalidFileError – if filename is not valid.
get_entry
get_entry(gate)
Gets the set of QuantumCircuits circuits from the library which equivalently implement the given Gate.
Parameterized circuits will have their parameters replaced with the corresponding entries from Gate.params.
Parameters
gate (Gate) – A Gate instance.
Returns
A list of equivalent QuantumCircuits. If empty,
library contains no known decompositions of Gate.
Returned circuits will be ordered according to their insertion in the library, from earliest to latest, from top to base. The ordering of the StandardEquivalenceLibrary will not generally be consistent across Qiskit versions.
Return type
List[QuantumCircuit]
has_entry
has_entry(gate)
Check if a library contains any decompositions for gate.
Parameters
gate (Gate) – A Gate instance.
Returns
True if gate has a known decomposition in the library.
False otherwise.
Return type
keys
keys()
Return list of keys to key to node index map.
Returns
Keys to the key to node index map.
Return type
List
node_index
node_index(key)
Return node index for a given key.
Parameters
key (Key) – Key to an equivalence.
Returns
Index to the node in the graph for the given key.
Return type
Int
set_entry
set_entry(gate, entry)
Set the equivalence record for a Gate. Future queries for the Gate will return only the circuits provided.
Parameterized Gates (those including qiskit.circuit.Parameters in their Gate.params) can be marked equivalent to parameterized circuits, provided the parameters match.
Parameters
- gate (Gate) – A Gate instance.
- entry (List['QuantumCircuit']) – A list of QuantumCircuits, each equivalently implementing the given Gate.