dimod.binary.Spin#

Spin(label: Hashable | None = None, bias: float | floating | integer = 1, dtype: dtype[Any] | None | type[Any] | _SupportsDType[dtype[Any]] | str | tuple[Any, int] | tuple[Any, SupportsIndex | Sequence[SupportsIndex]] | list[Any] | _DTypeDict | tuple[Any, Any] = None) → BinaryQuadraticModel[source]#

Return a binary quadratic model with a single spin variable.

Parameters:

  • label – Hashable label to identify the variable. Defaults to a generated uuid.UUID as a string.

  • bias – The bias to apply to the variable.

  • dtype – Data type for the returned binary quadratic model.

Returns:

A BinaryQuadraticModel representing a spin-valued binary variable.

Examples

This example generates a BQM to represent the polynomial, \(3s - 1.5\), where \(s\) is a binary variable with spin values \(\{-1, 1\}\).

>>> s = dimod.Spin('s')
>>> bqm = 3*s - 1.5
>>> print(bqm.to_polystring())
-1.5 + 3*s