SnapshotExpectationValue
SnapshotExpectationValue(label, op, single_shot=False, variance=False)
Bases: qiskit.providers.aer.extensions.snapshot.Snapshot
Snapshot instruction for supported methods of Qasm simulator.
Create an expectation value snapshot instruction.
Parameters
- label (str) – the snapshot label.
- op (Operator) – operator to snapshot.
- single_shot (bool) – return list for each shot rather than average [Default: False]
- variance (bool) – compute variance of values [Default: False]
Raises
ExtensionError – if snapshot is invalid.
This instruction has been deprecated and will be removed no earlier than 3 months from the 0.9.0 release date. It has been superseded by the qiskit.providers.aer.library.SaveExpectationValue
and qiskit.providers.aer.library.SaveExpectationValueVariance
instructions.
Methods
add_decomposition
SnapshotExpectationValue.add_decomposition(decomposition)
Add a decomposition of the instruction to the SessionEquivalenceLibrary.
assemble
SnapshotExpectationValue.assemble()
Assemble a QasmQobjInstruction for snapshot_expectation_value.
broadcast_arguments
SnapshotExpectationValue.broadcast_arguments(qargs, cargs)
Validation of the arguments.
Parameters
- qargs (List) – List of quantum bit arguments.
- cargs (List) – List of classical bit arguments.
Yields
Tuple(List, List) – A tuple with single arguments.
Raises
CircuitError – If the input is not valid. For example, the number of arguments does not match the gate expectation.
c_if
SnapshotExpectationValue.c_if(classical, val)
Set a classical equality condition on this instruction between the register or cbit classical
and value val
.
This is a setter method, not an additive one. Calling this multiple times will silently override any previously set condition; it does not stack.
copy
SnapshotExpectationValue.copy(name=None)
Copy of the instruction.
Parameters
name (str) – name to be given to the copied circuit, if None then the name stays the same.
Returns
a copy of the current instruction, with the name
updated if it was provided
Return type
define_snapshot_register
static SnapshotExpectationValue.define_snapshot_register(circuit, label=None, qubits=None)
Defines qubits to snapshot for all snapshot methods
inverse
SnapshotExpectationValue.inverse()
Special case. Return self.
is_parameterized
SnapshotExpectationValue.is_parameterized()
Return True .IFF. instruction is parameterized else False
mirror
SnapshotExpectationValue.mirror()
DEPRECATED: use instruction.reverse_ops().
Returns
a new instruction with sub-instructions
reversed.
Return type
qasm
SnapshotExpectationValue.qasm()
Return a default OpenQASM string for the instruction.
Derived instructions may override this to print in a different format (e.g. measure q[0] -> c[0];).
repeat
SnapshotExpectationValue.repeat(n)
Creates an instruction with gate repeated n amount of times.
Parameters
n (int) – Number of times to repeat the instruction
Returns
Containing the definition.
Return type
Raises
CircuitError – If n < 1.
reverse_ops
SnapshotExpectationValue.reverse_ops()
For a composite instruction, reverse the order of sub-instructions.
This is done by recursively reversing all sub-instructions. It does not invert any gate.
Returns
a new instruction with
sub-instructions reversed.
Return type
soft_compare
SnapshotExpectationValue.soft_compare(other)
Soft comparison between gates. Their names, number of qubits, and classical bit numbers must match. The number of parameters must match. Each parameter is compared. If one is a ParameterExpression then it is not taken into account.
Parameters
other (instruction) – other instruction.
Returns
are self and other equal up to parameter expressions.
Return type
bool
validate_parameter
SnapshotExpectationValue.validate_parameter(parameter)
Instruction parameters has no validation or normalization.
Attributes
condition_bits
Get Clbits in condition.
Return type
List
[Clbit
]
decompositions
Get the decompositions of the instruction from the SessionEquivalenceLibrary.
definition
Return definition in terms of other basic gates.
duration
Get the duration.
label
Return snapshot label
params
return instruction params.
snapshot_type
Return snapshot type
unit
Get the time unit of duration.