SparseVectorStateFn
class qiskit.opflow.state_fns.SparseVectorStateFn(*args, **kwargs)
Bases: StateFn
Deprecated: A class for sparse state functions and measurements in vector representation.
This class uses scipy.sparse.spmatrix for the internal representation.
The class qiskit.opflow.state_fns.sparse_vector_state_fn.SparseVectorStateFn is deprecated as of qiskit 0.24.0. It will be removed in the Qiskit 1.0 release. For code migration guidelines, visit https://qisk.it/opflow_migration(opens in a new tab).
Parameters
- primitive – The underlying sparse vector.
- coeff – A coefficient multiplying the state function.
- is_measurement – Whether the StateFn is a measurement operator
Raises
- ValueError(opens in a new tab) – If the primitive is not a column vector.
- ValueError(opens in a new tab) – If the number of elements in the primitive is not a power of 2.
Attributes
INDENTATION
Default value: ' '
coeff
A coefficient by which the state function is multiplied.
instance_id
Return the unique instance id.
is_measurement
Whether the StateFn object is a measurement Operator.
num_qubits
parameters
primitive
Type: spmatrix
The primitive which defines the behavior of the underlying State function.
settings
Return settings.
Methods
add
add(other)
Return Operator addition of self and other, overloaded by +.
Parameters
other (OperatorBase) – An OperatorBase with the same number of qubits as self, and in the same ‘Operator’, ‘State function’, or ‘Measurement’ category as self (i.e. the same type of underlying function).
Returns
An OperatorBase equivalent to the sum of self and other.
Return type
adjoint
adjoint()
Return a new Operator equal to the Operator’s adjoint (conjugate transpose), overloaded by ~. For StateFns, this also turns the StateFn into a measurement.
Returns
An OperatorBase equivalent to the adjoint of self.
Return type
equals
equals(other)
Evaluate Equality between Operators, overloaded by ==. Only returns True if self and other are of the same representation (e.g. a DictStateFn and CircuitStateFn will never be equal, even if their vector representations are equal), their underlying primitives are equal (this means for ListOps, OperatorStateFns, or EvolvedOps the equality is evaluated recursively downwards), and their coefficients are equal.
Parameters
other (OperatorBase) – The OperatorBase to compare to self.
Returns
A bool equal to the equality of self and other.
Return type
eval
eval(front=None)
Evaluate the Operator’s underlying function, either on a binary string or another Operator. A square binary Operator can be defined as a function taking a binary function to another binary function. This method returns the value of that function for a given StateFn or binary string. For example, op.eval('0110').eval('1110') can be seen as querying the Operator’s matrix representation by row 6 and column 14, and will return the complex value at those “indices.” Similarly for a StateFn, op.eval('1011') will return the complex value at row 11 of the vector representation of the StateFn, as all StateFns are defined to be evaluated from Zero implicitly (i.e. it is as if .eval('0000') is already called implicitly to always “indexing” from column 0).
If front is None, the matrix-representation of the operator is returned.
Parameters
front (str(opens in a new tab) |Dict(opens in a new tab)[str(opens in a new tab), complex(opens in a new tab)] | ndarray(opens in a new tab) |OperatorBase |Statevector | None) – The bitstring, dict of bitstrings (with values being coefficients), or StateFn to evaluated by the Operator’s underlying function, or None.
Returns
The output of the Operator’s evaluation function. If self is a StateFn, the result is a float or complex. If self is an Operator (PrimitiveOp, ComposedOp, SummedOp, EvolvedOp, etc.), the result is a StateFn. If front is None, the matrix-representation of the operator is returned, which is a MatrixOp for the operators and a VectorStateFn for state-functions. If either self or front contain proper ListOps (not ListOp subclasses), the result is an n-dimensional list of complex or StateFn results, resulting from the recursive evaluation by each OperatorBase in the ListOps.
Return type
primitive_strings
primitive_strings()
Return a set of strings describing the primitives contained in the Operator. For example, {'QuantumCircuit', 'Pauli'}. For hierarchical Operators, such as ListOps, this can help illuminate the primitives represented in the various recursive levels, and therefore which conversions can be applied.
Returns
A set of strings describing the primitives contained within the Operator.
Return type
sample
sample(shots=1024, massive=False, reverse_endianness=False)
Sample the state function as a normalized probability distribution. Returns dict of bitstrings in order of probability, with values being probability.
Parameters
- shots (int(opens in a new tab)) – The number of samples to take to approximate the State function.
- massive (bool(opens in a new tab)) – Whether to allow large conversions, e.g. creating a matrix representing over 16 qubits.
- reverse_endianness (bool(opens in a new tab)) – Whether to reverse the endianness of the bitstrings in the return dict to match Terra’s big-endianness.
Returns
A dict containing pairs sampled strings from the State function and sampling frequency divided by shots.
Return type
to_circuit_op
to_dict_fn
to_dict_fn()
Convert this state function to a DictStateFn.
Returns
A new DictStateFn equivalent to self.
Return type
to_matrix
to_matrix(massive=False)
Return NumPy representation of the Operator. Represents the evaluation of the Operator’s underlying function on every combination of basis binary strings. Warn if more than 16 qubits to force having to set massive=True if such a large vector is desired.
Returns
The NumPy ndarray equivalent to this Operator.
Return type
to_matrix_op
to_matrix_op(massive=False)
Return a VectorStateFn for this StateFn.
Parameters
massive (bool(opens in a new tab)) – Whether to allow large conversions, e.g. creating a matrix representing over 16 qubits.
Returns
A VectorStateFn equivalent to self.
Return type
to_spmatrix
to_spmatrix()
Return SciPy sparse matrix representation of the Operator. Represents the evaluation of the Operator’s underlying function on every combination of basis binary strings.
Returns
The SciPy spmatrix equivalent to this Operator.
Return type