95 lines
3.3 KiB
Plaintext
95 lines
3.3 KiB
Plaintext
---
|
||
title: LinearSystemObservable
|
||
description: API reference for qiskit.algorithms.linear_solvers.LinearSystemObservable
|
||
in_page_toc_min_heading_level: 1
|
||
python_api_type: class
|
||
python_api_name: qiskit.algorithms.linear_solvers.LinearSystemObservable
|
||
---
|
||
|
||
# LinearSystemObservable
|
||
|
||
<Class id="qiskit.algorithms.linear_solvers.LinearSystemObservable" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.23/qiskit/algorithms/linear_solvers/observables/linear_system_observable.py" signature="LinearSystemObservable" modifiers="class">
|
||
Bases: `abc.ABC`
|
||
|
||
The deprecated abstract class for linear system observables in Qiskit.
|
||
|
||
## Methods
|
||
|
||
### evaluate\_classically
|
||
|
||
<Function id="qiskit.algorithms.linear_solvers.LinearSystemObservable.evaluate_classically" signature="LinearSystemObservable.evaluate_classically(solution)" modifiers="abstract">
|
||
#### Calculates the analytical value of the given observable from the solution vector to the
|
||
|
||
linear system.
|
||
|
||
**Parameters**
|
||
|
||
**solution** (`Union`\[`array`, [`QuantumCircuit`](qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")]) – The solution to the system as a numpy array or the circuit that prepares it.
|
||
|
||
**Return type**
|
||
|
||
`float`
|
||
|
||
**Returns**
|
||
|
||
The value of the observable.
|
||
</Function>
|
||
|
||
### observable
|
||
|
||
<Function id="qiskit.algorithms.linear_solvers.LinearSystemObservable.observable" signature="LinearSystemObservable.observable(num_qubits)" modifiers="abstract">
|
||
The observable operator.
|
||
|
||
**Parameters**
|
||
|
||
**num\_qubits** (`int`) – The number of qubits on which the observable will be applied.
|
||
|
||
**Return type**
|
||
|
||
`Union`\[[`TensoredOp`](qiskit.opflow.list_ops.TensoredOp "qiskit.opflow.list_ops.tensored_op.TensoredOp"), `List`\[[`TensoredOp`](qiskit.opflow.list_ops.TensoredOp "qiskit.opflow.list_ops.tensored_op.TensoredOp")]]
|
||
|
||
**Returns**
|
||
|
||
The observable as a sum of Pauli strings.
|
||
</Function>
|
||
|
||
### observable\_circuit
|
||
|
||
<Function id="qiskit.algorithms.linear_solvers.LinearSystemObservable.observable_circuit" signature="LinearSystemObservable.observable_circuit(num_qubits)" modifiers="abstract">
|
||
The circuit implementing the observable.
|
||
|
||
**Parameters**
|
||
|
||
**num\_qubits** (`int`) – The number of qubits on which the observable will be applied.
|
||
|
||
**Return type**
|
||
|
||
`Union`\[[`QuantumCircuit`](qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit"), `List`\[[`QuantumCircuit`](qiskit.circuit.QuantumCircuit "qiskit.circuit.quantumcircuit.QuantumCircuit")]]
|
||
|
||
**Returns**
|
||
|
||
The observable as a QuantumCircuit.
|
||
</Function>
|
||
|
||
### post\_processing
|
||
|
||
<Function id="qiskit.algorithms.linear_solvers.LinearSystemObservable.post_processing" signature="LinearSystemObservable.post_processing(solution, num_qubits, scaling=1)" modifiers="abstract">
|
||
Evaluates the given observable on the solution to the linear system.
|
||
|
||
**Parameters**
|
||
|
||
* **solution** (`Union`\[`float`, `List`\[`float`]]) – The probability calculated from the circuit and the observable.
|
||
* **num\_qubits** (`int`) – The number of qubits where the observable was applied.
|
||
* **scaling** (`float`) – Scaling of the solution.
|
||
|
||
**Return type**
|
||
|
||
`float`
|
||
|
||
**Returns**
|
||
|
||
The value of the observable.
|
||
</Function>
|
||
</Class>
|
||
|