qiskit-documentation/docs/api/qiskit/0.24/qiskit.quantum_info.SparseP...

551 lines
23 KiB
Plaintext
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

---
title: SparsePauliOp
description: API reference for qiskit.quantum_info.SparsePauliOp
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.quantum_info.SparsePauliOp
---
<span id="qiskit-quantum-info-sparsepauliop" />
# qiskit.quantum\_info.SparsePauliOp
<Class id="qiskit.quantum_info.SparsePauliOp" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.16/qiskit/quantum_info/operators/symplectic/sparse_pauli_op.py" signature="SparsePauliOp(data, coeffs=None)" modifiers="class">
Sparse N-qubit operator in a Pauli basis representation.
This is a sparse representation of an N-qubit matrix [`Operator`](qiskit.quantum_info.Operator "qiskit.quantum_info.Operator") in terms of N-qubit [`PauliTable`](qiskit.quantum_info.PauliTable "qiskit.quantum_info.PauliTable") and complex coefficients.
It can be used for performing operator arithmetic for hundred of qubits if the number of non-zero Pauli basis terms is sufficiently small.
The Pauli basis components are stored as a [`PauliTable`](qiskit.quantum_info.PauliTable "qiskit.quantum_info.PauliTable") object and can be accessed using the [`table`](#qiskit.quantum_info.SparsePauliOp.table "qiskit.quantum_info.SparsePauliOp.table") attribute. The coefficients are stored as a complex Numpy array vector and can be accessed using the [`coeffs`](#qiskit.quantum_info.SparsePauliOp.coeffs "qiskit.quantum_info.SparsePauliOp.coeffs") attribute.
Initialize an operator object.
**Parameters**
* **data** ([*PauliTable*](qiskit.quantum_info.PauliTable "qiskit.quantum_info.PauliTable")) Pauli table of terms.
* **coeffs** (*np.ndarray*) complex coefficients for Pauli terms.
**Raises**
**QiskitError** If the input data or coeffs are invalid.
### \_\_init\_\_
<Function id="qiskit.quantum_info.SparsePauliOp.__init__" signature="__init__(data, coeffs=None)">
Initialize an operator object.
**Parameters**
* **data** ([*PauliTable*](qiskit.quantum_info.PauliTable "qiskit.quantum_info.PauliTable")) Pauli table of terms.
* **coeffs** (*np.ndarray*) complex coefficients for Pauli terms.
**Raises**
**QiskitError** If the input data or coeffs are invalid.
</Function>
## Methods
| | |
| ----------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- |
| [`__init__`](#qiskit.quantum_info.SparsePauliOp.__init__ "qiskit.quantum_info.SparsePauliOp.__init__")(data\[, coeffs]) | Initialize an operator object. |
| [`add`](#qiskit.quantum_info.SparsePauliOp.add "qiskit.quantum_info.SparsePauliOp.add")(other) | Return the linear operator self + other. |
| [`adjoint`](#qiskit.quantum_info.SparsePauliOp.adjoint "qiskit.quantum_info.SparsePauliOp.adjoint")() | Return the adjoint of the operator. |
| [`compose`](#qiskit.quantum_info.SparsePauliOp.compose "qiskit.quantum_info.SparsePauliOp.compose")(other\[, qargs, front]) | Return the composition channel self∘other. |
| [`conjugate`](#qiskit.quantum_info.SparsePauliOp.conjugate "qiskit.quantum_info.SparsePauliOp.conjugate")() | Return the conjugate of the operator. |
| [`copy`](#qiskit.quantum_info.SparsePauliOp.copy "qiskit.quantum_info.SparsePauliOp.copy")() | Make a deep copy of current operator. |
| [`dot`](#qiskit.quantum_info.SparsePauliOp.dot "qiskit.quantum_info.SparsePauliOp.dot")(other\[, qargs]) | Return the composition channel self∘other. |
| [`expand`](#qiskit.quantum_info.SparsePauliOp.expand "qiskit.quantum_info.SparsePauliOp.expand")(other) | Return the tensor product operator other ⊗ self. |
| [`from_list`](#qiskit.quantum_info.SparsePauliOp.from_list "qiskit.quantum_info.SparsePauliOp.from_list")(obj) | Construct from a list \[(pauli\_str, coeffs)] |
| [`from_operator`](#qiskit.quantum_info.SparsePauliOp.from_operator "qiskit.quantum_info.SparsePauliOp.from_operator")(obj\[, atol, rtol]) | Construct from an Operator objector. |
| [`input_dims`](#qiskit.quantum_info.SparsePauliOp.input_dims "qiskit.quantum_info.SparsePauliOp.input_dims")(\[qargs]) | Return tuple of input dimension for specified subsystems. |
| [`is_unitary`](#qiskit.quantum_info.SparsePauliOp.is_unitary "qiskit.quantum_info.SparsePauliOp.is_unitary")(\[atol, rtol]) | Return True if operator is a unitary matrix. |
| [`label_iter`](#qiskit.quantum_info.SparsePauliOp.label_iter "qiskit.quantum_info.SparsePauliOp.label_iter")() | Return a label representation iterator. |
| [`matrix_iter`](#qiskit.quantum_info.SparsePauliOp.matrix_iter "qiskit.quantum_info.SparsePauliOp.matrix_iter")(\[sparse]) | Return a matrix representation iterator. |
| [`multiply`](#qiskit.quantum_info.SparsePauliOp.multiply "qiskit.quantum_info.SparsePauliOp.multiply")(other) | Return the linear operator other \* self. |
| [`output_dims`](#qiskit.quantum_info.SparsePauliOp.output_dims "qiskit.quantum_info.SparsePauliOp.output_dims")(\[qargs]) | Return tuple of output dimension for specified subsystems. |
| [`power`](#qiskit.quantum_info.SparsePauliOp.power "qiskit.quantum_info.SparsePauliOp.power")(n) | Return the compose of a operator with itself n times. |
| [`reshape`](#qiskit.quantum_info.SparsePauliOp.reshape "qiskit.quantum_info.SparsePauliOp.reshape")(\[input\_dims, output\_dims]) | Return a shallow copy with reshaped input and output subsystem dimensions. |
| [`set_atol`](#qiskit.quantum_info.SparsePauliOp.set_atol "qiskit.quantum_info.SparsePauliOp.set_atol")(value) | Set the class default absolute tolerance parameter for float comparisons. |
| [`set_rtol`](#qiskit.quantum_info.SparsePauliOp.set_rtol "qiskit.quantum_info.SparsePauliOp.set_rtol")(value) | Set the class default relative tolerance parameter for float comparisons. |
| [`simplify`](#qiskit.quantum_info.SparsePauliOp.simplify "qiskit.quantum_info.SparsePauliOp.simplify")(\[atol, rtol]) | Simplify PauliTable by combining duplicaties and removing zeros. |
| [`subtract`](#qiskit.quantum_info.SparsePauliOp.subtract "qiskit.quantum_info.SparsePauliOp.subtract")(other) | Return the linear operator self - other. |
| [`tensor`](#qiskit.quantum_info.SparsePauliOp.tensor "qiskit.quantum_info.SparsePauliOp.tensor")(other) | Return the tensor product operator self ⊗ other. |
| [`to_list`](#qiskit.quantum_info.SparsePauliOp.to_list "qiskit.quantum_info.SparsePauliOp.to_list")(\[array]) | Convert to a list Pauli string labels and coefficients. |
| [`to_matrix`](#qiskit.quantum_info.SparsePauliOp.to_matrix "qiskit.quantum_info.SparsePauliOp.to_matrix")(\[sparse]) | Convert to a dense or sparse matrix. |
| [`to_operator`](#qiskit.quantum_info.SparsePauliOp.to_operator "qiskit.quantum_info.SparsePauliOp.to_operator")() | Convert to a matrix Operator object |
| [`transpose`](#qiskit.quantum_info.SparsePauliOp.transpose "qiskit.quantum_info.SparsePauliOp.transpose")() | Return the transpose of the operator. |
## Attributes
| | |
| ------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------- |
| [`atol`](#qiskit.quantum_info.SparsePauliOp.atol "qiskit.quantum_info.SparsePauliOp.atol") | The default absolute tolerance parameter for float comparisons. |
| [`coeffs`](#qiskit.quantum_info.SparsePauliOp.coeffs "qiskit.quantum_info.SparsePauliOp.coeffs") | Return the Pauli coefficients. |
| [`dim`](#qiskit.quantum_info.SparsePauliOp.dim "qiskit.quantum_info.SparsePauliOp.dim") | Return tuple (input\_shape, output\_shape). |
| [`num_qubits`](#qiskit.quantum_info.SparsePauliOp.num_qubits "qiskit.quantum_info.SparsePauliOp.num_qubits") | Return the number of qubits if a N-qubit operator or None otherwise. |
| [`qargs`](#qiskit.quantum_info.SparsePauliOp.qargs "qiskit.quantum_info.SparsePauliOp.qargs") | Return the qargs for the operator. |
| [`rtol`](#qiskit.quantum_info.SparsePauliOp.rtol "qiskit.quantum_info.SparsePauliOp.rtol") | The relative tolerance parameter for float comparisons. |
| [`size`](#qiskit.quantum_info.SparsePauliOp.size "qiskit.quantum_info.SparsePauliOp.size") | The number of Pauli of Pauli terms in the operator. |
| [`table`](#qiskit.quantum_info.SparsePauliOp.table "qiskit.quantum_info.SparsePauliOp.table") | Return the the PauliTable. |
### add
<Function id="qiskit.quantum_info.SparsePauliOp.add" signature="add(other)">
Return the linear operator self + other.
DEPRECATED: use `operator + other` instead.
**Parameters**
**other** (*BaseOperator*) an operator object.
**Returns**
the operator self + other.
**Return type**
BaseOperator
</Function>
### adjoint
<Function id="qiskit.quantum_info.SparsePauliOp.adjoint" signature="adjoint()">
Return the adjoint of the operator.
</Function>
### atol
<Attribute id="qiskit.quantum_info.SparsePauliOp.atol">
The default absolute tolerance parameter for float comparisons.
</Attribute>
### coeffs
<Attribute id="qiskit.quantum_info.SparsePauliOp.coeffs">
Return the Pauli coefficients.
</Attribute>
### compose
<Function id="qiskit.quantum_info.SparsePauliOp.compose" signature="compose(other, qargs=None, front=False)">
Return the composition channel self∘other.
**Parameters**
* **other** ([*SparsePauliOp*](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")) an operator object.
* **qargs** (*list or None*) a list of subsystem positions to compose other on.
* **front** (*bool or None*) If False compose in standard order other(self(input)) otherwise compose in reverse order self(other(input)) \[default: False]
**Returns**
The composed operator.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
**Raises**
* **QiskitError** if other cannot be converted to an Operator or has
* **incompatible dimensions.**
</Function>
### conjugate
<Function id="qiskit.quantum_info.SparsePauliOp.conjugate" signature="conjugate()">
Return the conjugate of the operator.
</Function>
### copy
<Function id="qiskit.quantum_info.SparsePauliOp.copy" signature="copy()">
Make a deep copy of current operator.
</Function>
### dim
<Attribute id="qiskit.quantum_info.SparsePauliOp.dim">
Return tuple (input\_shape, output\_shape).
</Attribute>
### dot
<Function id="qiskit.quantum_info.SparsePauliOp.dot" signature="dot(other, qargs=None)">
Return the composition channel self∘other.
**Parameters**
* **other** ([*SparsePauliOp*](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")) an operator object.
* **qargs** (*list or None*) a list of subsystem positions to compose other on.
**Returns**
The composed operator.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
**Raises**
* **QiskitError** if other cannot be converted to an Operator or has
* **incompatible dimensions.**
</Function>
### expand
<Function id="qiskit.quantum_info.SparsePauliOp.expand" signature="expand(other)">
Return the tensor product operator other ⊗ self.
**Parameters**
**other** ([*SparsePauliOp*](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")) an operator object.
**Returns**
the tensor product operator other ⊗ self.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
**Raises**
**QiskitError** if other cannot be converted to a SparsePauliOp operator.
</Function>
### from\_list
<Function id="qiskit.quantum_info.SparsePauliOp.from_list" signature="from_list(obj)" modifiers="static">
Construct from a list \[(pauli\_str, coeffs)]
</Function>
### from\_operator
<Function id="qiskit.quantum_info.SparsePauliOp.from_operator" signature="from_operator(obj, atol=None, rtol=None)" modifiers="static">
Construct from an Operator objector.
Note that the cost of this contruction is exponential as it involves taking inner products with every element of the N-qubit Pauli basis.
**Parameters**
* **obj** ([*Operator*](qiskit.quantum_info.Operator "qiskit.quantum_info.Operator")) an N-qubit operator.
* **atol** (*float*) Optional. Absolute tolerance for checking if coefficients are zero (Default: 1e-8).
* **rtol** (*float*) Optinoal. relative tolerance for checking if coefficients are zero (Default: 1e-5).
**Returns**
the SparsePauliOp representation of the operator.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
**Raises**
**QiskitError** if the input operator is not an N-qubit operator.
</Function>
### input\_dims
<Function id="qiskit.quantum_info.SparsePauliOp.input_dims" signature="input_dims(qargs=None)">
Return tuple of input dimension for specified subsystems.
</Function>
### is\_unitary
<Function id="qiskit.quantum_info.SparsePauliOp.is_unitary" signature="is_unitary(atol=None, rtol=None)">
Return True if operator is a unitary matrix.
**Parameters**
* **atol** (*float*) Optional. Absolute tolerance for checking if coefficients are zero (Default: 1e-8).
* **rtol** (*float*) Optinoal. relative tolerance for checking if coefficients are zero (Default: 1e-5).
**Returns**
True if the operator is unitary, False otherwise.
**Return type**
bool
</Function>
### label\_iter
<Function id="qiskit.quantum_info.SparsePauliOp.label_iter" signature="label_iter()">
Return a label representation iterator.
This is a lazy iterator that converts each term in the SparsePauliOp into a tuple (label, coeff). To convert the entire table to labels use the `to_labels()` method.
**Returns**
label iterator object for the PauliTable.
**Return type**
LabelIterator
</Function>
### matrix\_iter
<Function id="qiskit.quantum_info.SparsePauliOp.matrix_iter" signature="matrix_iter(sparse=False)">
Return a matrix representation iterator.
This is a lazy iterator that converts each term in the SparsePauliOp into a matrix as it is used. To convert to a single matrix use the [`to_matrix()`](#qiskit.quantum_info.SparsePauliOp.to_matrix "qiskit.quantum_info.SparsePauliOp.to_matrix") method.
**Parameters**
**sparse** (*bool*) optionally return sparse CSR matrices if True, otherwise return Numpy array matrices (Default: False)
**Returns**
matrix iterator object for the PauliTable.
**Return type**
MatrixIterator
</Function>
### multiply
<Function id="qiskit.quantum_info.SparsePauliOp.multiply" signature="multiply(other)">
Return the linear operator other \* self.
DEPRECATED: use `other * operator` instead.
**Parameters**
**other** (*complex*) a complex number.
**Returns**
the linear operator other \* self.
**Return type**
BaseOperator
**Raises**
**NotImplementedError** if subclass does not support multiplication.
</Function>
### num\_qubits
<Attribute id="qiskit.quantum_info.SparsePauliOp.num_qubits">
Return the number of qubits if a N-qubit operator or None otherwise.
</Attribute>
### output\_dims
<Function id="qiskit.quantum_info.SparsePauliOp.output_dims" signature="output_dims(qargs=None)">
Return tuple of output dimension for specified subsystems.
</Function>
### power
<Function id="qiskit.quantum_info.SparsePauliOp.power" signature="power(n)">
Return the compose of a operator with itself n times.
**Parameters**
**n** (*int*) the number of times to compose with self (n>0).
**Returns**
the n-times composed operator.
**Return type**
BaseOperator
**Raises**
**QiskitError** if the input and output dimensions of the operator are not equal, or the power is not a positive integer.
</Function>
### qargs
<Attribute id="qiskit.quantum_info.SparsePauliOp.qargs">
Return the qargs for the operator.
</Attribute>
### reshape
<Function id="qiskit.quantum_info.SparsePauliOp.reshape" signature="reshape(input_dims=None, output_dims=None)">
Return a shallow copy with reshaped input and output subsystem dimensions.
**Arg:**
**input\_dims (None or tuple): new subsystem input dimensions.**
If None the original input dims will be preserved \[Default: None].
**output\_dims (None or tuple): new subsystem output dimensions.**
If None the original output dims will be preserved \[Default: None].
**Returns**
returns self with reshaped input and output dimensions.
**Return type**
BaseOperator
**Raises**
**QiskitError** if combined size of all subsystem input dimension or subsystem output dimensions is not constant.
</Function>
### rtol
<Attribute id="qiskit.quantum_info.SparsePauliOp.rtol">
The relative tolerance parameter for float comparisons.
</Attribute>
### set\_atol
<Function id="qiskit.quantum_info.SparsePauliOp.set_atol" signature="set_atol(value)" modifiers="classmethod">
Set the class default absolute tolerance parameter for float comparisons.
DEPRECATED: use operator.atol = value instead
</Function>
### set\_rtol
<Function id="qiskit.quantum_info.SparsePauliOp.set_rtol" signature="set_rtol(value)" modifiers="classmethod">
Set the class default relative tolerance parameter for float comparisons.
DEPRECATED: use operator.rtol = value instead
</Function>
### simplify
<Function id="qiskit.quantum_info.SparsePauliOp.simplify" signature="simplify(atol=None, rtol=None)">
Simplify PauliTable by combining duplicaties and removing zeros.
**Parameters**
* **atol** (*float*) Optional. Absolute tolerance for checking if coefficients are zero (Default: 1e-8).
* **rtol** (*float*) Optinoal. relative tolerance for checking if coefficients are zero (Default: 1e-5).
**Returns**
the simplified SparsePauliOp operator.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
</Function>
### size
<Attribute id="qiskit.quantum_info.SparsePauliOp.size">
The number of Pauli of Pauli terms in the operator.
</Attribute>
### subtract
<Function id="qiskit.quantum_info.SparsePauliOp.subtract" signature="subtract(other)">
Return the linear operator self - other.
DEPRECATED: use `operator - other` instead.
**Parameters**
**other** (*BaseOperator*) an operator object.
**Returns**
the operator self - other.
**Return type**
BaseOperator
</Function>
### table
<Attribute id="qiskit.quantum_info.SparsePauliOp.table">
Return the the PauliTable.
</Attribute>
### tensor
<Function id="qiskit.quantum_info.SparsePauliOp.tensor" signature="tensor(other)">
Return the tensor product operator self ⊗ other.
**Parameters**
**other** ([*SparsePauliOp*](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")) a operator subclass object.
**Returns**
the tensor product operator self ⊗ other.
**Return type**
[SparsePauliOp](#qiskit.quantum_info.SparsePauliOp "qiskit.quantum_info.SparsePauliOp")
**Raises**
**QiskitError** if other cannot be converted to a SparsePauliOp operator.
</Function>
### to\_list
<Function id="qiskit.quantum_info.SparsePauliOp.to_list" signature="to_list(array=False)">
Convert to a list Pauli string labels and coefficients.
For operators with a lot of terms converting using the `array=True` kwarg will be more efficient since it allocates memory for the full Numpy array of labels in advance.
**Parameters**
**array** (*bool*) return a Numpy array if True, otherwise return a list (Default: False).
**Returns**
List of pairs (label, coeff) for rows of the PauliTable.
**Return type**
list or array
</Function>
### to\_matrix
<Function id="qiskit.quantum_info.SparsePauliOp.to_matrix" signature="to_matrix(sparse=False)">
Convert to a dense or sparse matrix.
**Parameters**
**sparse** (*bool*) if True return a sparse CSR matrix, otherwise return dense Numpy array (Default: False).
**Returns**
A dense matrix if sparse=False. csr\_matrix: A sparse matrix in CSR format if sparse=True.
**Return type**
array
</Function>
### to\_operator
<Function id="qiskit.quantum_info.SparsePauliOp.to_operator" signature="to_operator()">
Convert to a matrix Operator object
</Function>
### transpose
<Function id="qiskit.quantum_info.SparsePauliOp.transpose" signature="transpose()">
Return the transpose of the operator.
</Function>
</Class>