def to_coo(self, fp=None, vartype_header=False):
"""Serialize the binary quadratic model to a COOrdinate format encoding.
COOrdinate_ is a sparse encoding for binary quadratic models.
.. _COOrdinate: https://en.wikipedia.org/wiki/Sparse_matrix#Coordinate_list_(COO)
Args:
fp (file, optional):
`.write()`-supporting `file object`_ to save the linear and quadratic biases
of a binary quadratic model to. The model is stored as a list of 3-tuples,
(i, j, bias), where :math:`i=j` for linear biases. If not provided,
returns a string.
vartype_header (bool, optional, default=False):
If true, the binary quadratic model's variable type as prepended to the
string or file as a header.
.. _file object: https://docs.python.org/3/glossary.html#term-file-object
.. note:: Variables must use index lables (numeric lables). Binary quadratic
models saved to COOrdinate format encoding do not preserve offsets.
.. note:: This method will be deprecated in the future. The preferred
pattern is to use :func:`~dimod.serialization.coo.dump` or
:func:`~dimod.serialization.coo.dumps` directly.
"""
import dimod.serialization.coo as coo
if fp is None:
return coo.dumps(self, vartype_header)
else:
coo.dump(self, fp, vartype_header)
def test_dumps_sortable_SPIN_with_header(self):
bqm = dimod.BinaryQuadraticModel.from_ising({0: 1.}, {
(0, 1): 2,
(2, 3): .4
})
s = coo.dumps(bqm, vartype_header=True)
contents = "# vartype=SPIN\n0 0 1.000000\n0 1 2.000000\n2 3 0.400000"
self.assertEqual(s, contents)
def test_functional_string_empty_SPIN(self):
bqm = dimod.BinaryQuadraticModel.empty(dimod.SPIN)
s = coo.dumps(bqm)
new_bqm = coo.loads(s, dimod.BinaryQuadraticModel, dimod.SPIN)
self.assertEqual(bqm, new_bqm)
def test_dumps_sortable_SPIN(self):
bqm = dimod.BinaryQuadraticModel.from_ising({0: 1.}, {
(0, 1): 2,
(2, 3): .4
})
s = coo.dumps(bqm)
contents = "0 0 1.000000\n0 1 2.000000\n2 3 0.400000"
self.assertEqual(s, contents)
def test_dumps_sortable_BINARY_with_header(self):
bqm = dimod.BinaryQuadraticModel.from_qubo({
(0, 0): 1.,
(0, 1): 2,
(2, 3): .4
})
s = coo.dumps(bqm, vartype_header=True)
contents = "# vartype=BINARY\n0 0 1.000000\n0 1 2.000000\n2 3 0.400000"
self.assertEqual(s, contents)
def test_conflicting_vartype(self):
bqm = dimod.BinaryQuadraticModel({0: 1.}, {
(0, 1): 2,
(2, 3): .4
}, 0.0, dimod.SPIN)
s = coo.dumps(bqm, vartype_header=True)
with self.assertRaises(ValueError):
coo.loads(s, dimod.BinaryQuadraticModel, dimod.BINARY)
def test_no_vartype(self):
bqm = dimod.BinaryQuadraticModel({0: 1.}, {
(0, 1): 2,
(2, 3): .4
}, 0.0, dimod.SPIN)
s = coo.dumps(bqm)
with self.assertRaises(ValueError):
coo.loads(s, dimod.BinaryQuadraticModel)
def test_functional_SPIN_vartypeheader(self):
bqm = dimod.BinaryQuadraticModel({0: 1.}, {
(0, 1): 2,
(2, 3): .4
}, 0.0, dimod.SPIN)
s = coo.dumps(bqm, vartype_header=True)
new_bqm = coo.loads(s, dimod.BinaryQuadraticModel)
self.assertEqual(bqm, new_bqm)
def test_functional_string_SPIN(self):
bqm = dimod.BinaryQuadraticModel({0: 1.}, {
(0, 1): 2,
(2, 3): .4
}, 0.0, dimod.SPIN)
s = coo.dumps(bqm)
new_bqm = coo.loads(s, dimod.BinaryQuadraticModel, dimod.SPIN)
self.assertEqual(bqm, new_bqm)
def test_dumps_empty_SPIN(self):
bqm = dimod.BinaryQuadraticModel.empty(dimod.BINARY)
s = coo.dumps(bqm)
self.assertEqual(s, '')
