dimod.BinaryQuadraticModel.fix_variable

BinaryQuadraticModel.fix_variable(v, value)

Fix the value of a variable and remove it from a binary quadratic model.

Parameters:

• v (variable) – Variable in the binary quadratic model to be fixed.
• value (int) – Value assigned to the variable. Values must match the Vartype of the binary quadratic model.

Examples

This example creates a binary quadratic model with one variable and fixes its value.

>>> import dimod
>>> bqm = dimod.BinaryQuadraticModel({'a': -.5}, {}, 0.0, dimod.SPIN)
>>> bqm.fix_variable('a', -1)
>>> bqm.offset
0.5
>>> 'a' in bqm
False

This example creates a binary quadratic model with two variables and fixes the value of one.

>>> import dimod
>>> bqm = dimod.BinaryQuadraticModel({'a': -.5, 'b': 0.}, {('a', 'b'): -1}, 0.0, dimod.SPIN)
>>> bqm.fix_variable('a', -1)
>>> bqm.offset
0.5
>>> bqm.linear['b']
1.0
>>> len(bqm.quadratic)
0