dwavebinarycsp.Constraint.from_configurations#

classmethod Constraint.from_configurations(configurations, variables, vartype, name=None)[source]#

Construct a constraint from valid configurations.

Parameters:

configurations (iterable[tuple]) – Valid configurations of the variables. Each configuration is a tuple of variable assignments ordered by variables.
variables (iterable) – Iterable of variable labels.
vartype (Vartype/str/set) –
Variable type for the constraint. Accepted input values:
- SPIN, 'SPIN', {-1, 1}
- BINARY, 'BINARY', {0, 1}
name (string, optional, default='Constraint') – Name for the constraint.

Examples

This example creates a constraint that variables a and b are not equal.

>>> const = dwavebinarycsp.Constraint.from_configurations([(0, 1), (1, 0)],
...                   ['a', 'b'], dwavebinarycsp.BINARY)
>>> print(const.name)
Constraint
>>> (0, 0) in const.configurations   # Order matches variables: a,b
False

This example creates a constraint based on specified valid configurations that represents an OR gate for spin variables.

>>> const = dwavebinarycsp.Constraint.from_configurations(
...           [(-1, -1, -1), (1, -1, 1), (1, 1, -1), (1, 1, 1)],
...           ['y', 'x1', 'x2'],
...           dwavebinarycsp.SPIN, name='or_spin')
>>> print(const.name)
or_spin
>>> (1, 1, -1) in const.configurations   # Order matches variables: y,x1,x2
True