OperatorTrait

class OperatorTrait(*args, **kwargs)

Bases: Protocol

A protocol indicating all methods implemented by operator classes.

Attributes

groups

Returns the groups indices.

Methods

adjoint()

Returns the adjoint of this operator.

Return type:

Self

equiv(other, atol)

Checks this operator with another for equivalence up to the specified absolute tolerance.

Parameters:
Return type:

bool

classmethod from_terms(terms)

Constructs a new operator from an iterator (see also iter_terms()).

Parameters:

terms (Iterable)

Return type:

Self

classmethod from_terms_with_groups(terms)

Constructs a new operator from an iterator (see also iter_terms_with_groups()).

Parameters:

terms (Iterable)

Return type:

Self

get_coeffs()

Returns the term coefficients.

Return type:

list[complex]

get_support()

Returns the set of mode indices which this operator acts upon.

Return type:

frozenset[int]

group_weights()

Returns the mean absolute coefficient magnitude of each group.

This is equivalent to (but cheaper than) reducing get_coeffs() and groups down to one value per group in NumPy, because it does not copy one value per ungrouped term out of the operator just to aggregate it away again.

Return type:

list[float] | None

has_groups()

Returns whether this operator tracks group indices.

This is equivalent to (but cheaper than) checking op.groups is not None, because it does not copy the group indices out of the operator in order to inspect them.

Return type:

bool

ichop(atol)

Trims coefficients below the absolute tolerance from this operator.

Parameters:

atol (float)

is_hermitian(atol=1e-08)

Returns whether this operator is Hermitian.

The check reduces the difference of this operator and its adjoint() to a normal form (see normal_ordered()) and compares the result against zero(). It is therefore only as strong as the normal form that the specific operator type reduces through.

Note

A True result is always reliable. A False result is reliable only for operator types whose normal form is a genuine canonical form; for the others this check is conservative and can return False for an operator that is in fact Hermitian. Consult the specific implementation to find out which of the two applies.

Parameters:

atol (float) – The numerical accuracy upto which coefficients are considered equal. This value defaults to 1e-8.

Returns:

Whether this operator is Hermitian.

Return type:

bool

iter_terms()

Iterates over the terms of this operator.

Return type:

Iterator

iter_terms_with_groups()

Iterates over the terms of this operator with their group indices.

Return type:

Iterator

normal_ordered(*args, **kwargs)

Returns the normal-ordered form of this operator.

Note

A specific implementation of this method may take additional arguments.

Return type:

Self

num_groups()

Returns the number of groups.

Return type:

int | None

classmethod one()

Constructs the multiplicative identity operator.

Return type:

Self

relabel_modes(permutation)

Relabels the modes of the operator.

Parameters:

permutation (list[int])

Return type:

Self

simplify(atol)

Simplifies the terms of this operator, discarding those below the absolute tolerance.

Parameters:

atol (float)

Return type:

Self

split_out_groups(group_indices=None)

Splits this operator into an optional list of new operators based on its groups.

Note

If group_indices is omitted, every group is built, in index order. Otherwise, only the requested indices are built, in the given order.

Parameters:

group_indices (Sequence[int] | None)

Return type:

list[Self]

classmethod zero()

Constructs the additive identity operator.

Return type:

Self