def __init__(self, k_landmarks, m_ambient):
super(PreShapeMetric,
self).__init__(dim=m_ambient * (k_landmarks - 1) - 1,
default_point_type="matrix")
self.embedding_metric = MatricesMetric(k_landmarks, m_ambient)
self.sphere_metric = Hypersphere(m_ambient * k_landmarks - 1).metric
self.k_landmarks = k_landmarks
self.m_ambient = m_ambient
def __init__(self, m, n, **kwargs):
if "dim" not in kwargs.keys():
kwargs["dim"] = m * n
super(FullRankMatrices, self).__init__(ambient_space=Matrices(m, n),
metric=MatricesMetric(m, n),
**kwargs)
self.rank = min(m, n)
def __init__(self, n):
super(BuresWassersteinBundle, self).__init__(
n=n,
base=SPDMatrices(n),
group=SpecialOrthogonal(n),
ambient_metric=MatricesMetric(n, n),
)
def setUp(self):
gs.random.seed(0)
n = 3
self.base = SPDMatrices(n)
self.base_metric = SPDMetricBuresWasserstein(n)
self.group = SpecialOrthogonal(n)
self.bundle = FiberBundle(GeneralLinear(n),
base=self.base,
group=self.group)
self.quotient_metric = QuotientMetric(self.bundle,
ambient_metric=MatricesMetric(
n, n))
def submersion(point):
return GeneralLinear.mul(point, GeneralLinear.transpose(point))
def tangent_submersion(tangent_vec, base_point):
product = GeneralLinear.mul(base_point,
GeneralLinear.transpose(tangent_vec))
return 2 * GeneralLinear.to_symmetric(product)
def horizontal_lift(tangent_vec, point, base_point=None):
if base_point is None:
base_point = submersion(point)
sylvester = gs.linalg.solve_sylvester(base_point, base_point,
tangent_vec)
return GeneralLinear.mul(sylvester, point)
self.bundle.submersion = submersion
self.bundle.tangent_submersion = tangent_submersion
self.bundle.horizontal_lift = horizontal_lift
self.bundle.lift = gs.linalg.cholesky
def __init__(self, n, k):
super(BuresWassersteinBundle, self).__init__(
n=n,
k=k,
group=SpecialOrthogonal(k),
ambient_metric=MatricesMetric(n, k),
)
def __init__(self, n, k, **kwargs):
kwargs.setdefault("dim", n * k)
kwargs.setdefault("metric", MatricesMetric(n, k))
super(FullRankMatrices, self).__init__(ambient_space=Matrices(n, k),
**kwargs)
self.rank = min(n, k)
self.n = n
self.k = k
def __init__(self, n, **kwargs):
super(SymmetricMatrices, self).__init__(
dim=int(n * (n + 1) / 2),
shape=(n, n),
metric=MatricesMetric(n, n),
default_point_type="matrix",
)
self.n = n
def __init__(self, n, **kwargs):
kwargs.setdefault("metric", MatricesMetric(n, n))
super(LowerTriangularMatrices,
self).__init__(dim=int(n * (n + 1) / 2),
shape=(n, n),
default_point_type="matrix",
**kwargs)
self.n = n
def test_mean_matrices_shape(self):
m, n = (2, 2)
point = gs.array([[1., 4.], [2., 3.]])
metric = MatricesMetric(m, n)
mean = FrechetMean(metric=metric, point_type='matrix')
points = [point, point, point]
mean.fit(points)
result = mean.estimate_
self.assertAllClose(gs.shape(result), (m, n))
def test_mean_matrices(self):
m, n = (2, 2)
point = gs.array([[1.0, 4.0], [2.0, 3.0]])
metric = MatricesMetric(m, n)
mean = FrechetMean(metric=metric, point_type="matrix")
points = [point, point, point]
mean.fit(points)
result = mean.estimate_
expected = point
self.assertAllClose(result, expected)
def test_power_euclidean_inner_product(self):
"""Test of SPDMetricEuclidean.inner_product method."""
base_point = gs.array([[1., 0., 0.], [0., 2.5, 1.5], [0., 1.5, 2.5]])
tangent_vec = gs.array([[2., 1., 1.], [1., .5, .5], [1., .5, .5]])
metric = SPDMetricEuclidean(3, power_euclidean=.5)
result = metric.inner_product(tangent_vec, tangent_vec, base_point)
expected = 3472 / 576
self.assertAllClose(result, expected)
result = self.metric_euclidean.inner_product(tangent_vec, tangent_vec,
base_point)
expected = MatricesMetric(3, 3).inner_product(tangent_vec, tangent_vec)
self.assertAllClose(result, expected)
def dist(self, point_a, point_b):
"""Compute log euclidean distance.
Parameters
----------
point_a : array-like, shape=[..., dim]
Point.
point_b : array-like, shape=[..., dim]
Point.
Returns
-------
dist : array-like, shape=[...,]
Distance.
"""
log_a = SPDMatrices.logm(point_a)
log_b = SPDMatrices.logm(point_b)
return MatricesMetric.norm(log_a - log_b)
class PreShapeMetric(RiemannianMetric):
"""Procrustes metric on the pre-shape space.
Parameters
----------
k_landmarks : int
Number of landmarks
m_ambient : int
Number of coordinates of each landmark.
"""
def __init__(self, k_landmarks, m_ambient):
super(PreShapeMetric,
self).__init__(dim=m_ambient * (k_landmarks - 1) - 1,
default_point_type="matrix")
self.embedding_metric = MatricesMetric(k_landmarks, m_ambient)
self.sphere_metric = Hypersphere(m_ambient * k_landmarks - 1).metric
self.k_landmarks = k_landmarks
self.m_ambient = m_ambient
def inner_product(self, tangent_vec_a, tangent_vec_b, base_point=None):
"""Compute the inner-product of two tangent vectors at a base point.
Parameters
----------
tangent_vec_a : array-like, shape=[..., k_landmarks, m_ambient]
First tangent vector at base point.
tangent_vec_b : array-like, shape=[..., k_landmarks, m_ambient]
Second tangent vector at base point.
base_point : array-like, shape=[..., dk_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
inner_prod : array-like, shape=[...,]
Inner-product of the two tangent vectors.
"""
inner_prod = self.embedding_metric.inner_product(
tangent_vec_a, tangent_vec_b, base_point)
return inner_prod
def exp(self, tangent_vec, base_point, **kwargs):
"""Compute the Riemannian exponential of a tangent vector.
Parameters
----------
tangent_vec : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at a base point.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
exp : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space equal to the Riemannian exponential
of tangent_vec at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_tan = gs.reshape(tangent_vec, (-1, self.sphere_metric.dim + 1))
flat_exp = self.sphere_metric.exp(flat_tan, flat_bp)
return gs.reshape(flat_exp, tangent_vec.shape)
def log(self, point, base_point, **kwargs):
"""Compute the Riemannian logarithm of a point.
Parameters
----------
point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
log : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at the base point equal to the Riemannian logarithm
of point at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_pt = gs.reshape(point, (-1, self.sphere_metric.dim + 1))
flat_log = self.sphere_metric.log(flat_pt, flat_bp)
try:
log = gs.reshape(flat_log, base_point.shape)
except (RuntimeError, check_tf_error(ValueError,
"InvalidArgumentError")):
log = gs.reshape(flat_log, point.shape)
return log
def curvature(self, tangent_vec_a, tangent_vec_b, tangent_vec_c,
base_point):
r"""Compute the curvature.
For three tangent vectors at a base point :math:`x,y,z`,
the curvature is defined by
:math:`R(X, Y)Z = \nabla_{[X,Y]}Z
- \nabla_X\nabla_Y Z + - \nabla_Y\nabla_X Z`, where :math:`\nabla`
is the Levi-Civita connection. In the case of the hypersphere,
we have the closed formula
:math:`R(X,Y)Z = \langle X, Z \rangle Y - \langle Y,Z \rangle X`.
Parameters
----------
tangent_vec_a : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at `base_point`.
tangent_vec_b : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at `base_point`.
tangent_vec_c : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at `base_point`.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the group. Optional, default is the identity.
Returns
-------
curvature : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at `base_point`.
"""
max_shape = base_point.shape
for arg in [tangent_vec_a, tangent_vec_b, tangent_vec_c]:
if arg.ndim >= 3:
max_shape = arg.shape
flat_shape = (-1, self.sphere_metric.dim + 1)
flat_a = gs.reshape(tangent_vec_a, flat_shape)
flat_b = gs.reshape(tangent_vec_b, flat_shape)
flat_c = gs.reshape(tangent_vec_c, flat_shape)
flat_bp = gs.reshape(base_point, flat_shape)
curvature = self.sphere_metric.curvature(flat_a, flat_b, flat_c,
flat_bp)
curvature = gs.reshape(curvature, max_shape)
return curvature
def curvature_derivative(
self,
tangent_vec_a,
tangent_vec_b=None,
tangent_vec_c=None,
tangent_vec_d=None,
base_point=None,
):
r"""Compute the covariant derivative of the curvature.
For four vectors fields :math:`H|_P = tangent\_vec\_a, X|_P =
tangent\_vec\_b, Y|_P = tangent\_vec\_c, Z|_P = tangent\_vec\_d` with
tangent vector value specified in argument at the base point `P`,
the covariant derivative of the curvature
:math:`(\nabla_H R)(X, Y) Z |_P` is computed at the base point P.
Since the sphere is a constant curvature space this
vanishes identically.
Parameters
----------
tangent_vec_a : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at `base_point` along which the curvature is
derived.
tangent_vec_b : array-like, shape=[..., k_landmarks, m_ambient]
Unused tangent vector at `base_point` (since curvature derivative
vanishes).
tangent_vec_c : array-like, shape=[..., k_landmarks, m_ambient]
Unused tangent vector at `base_point` (since curvature derivative
vanishes).
tangent_vec_d : array-like, shape=[..., k_landmarks, m_ambient]
Unused tangent vector at `base_point` (since curvature derivative
vanishes).
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Unused point on the group.
Returns
-------
curvature_derivative : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at base point.
"""
return gs.zeros_like(tangent_vec_a)
def parallel_transport(self,
tangent_vec,
base_point,
direction=None,
end_point=None):
"""Compute the Riemannian parallel transport of a tangent vector.
Parameters
----------
tangent_vec : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at a base point.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
direction : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at a base point.
Optional, default : None.
end_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space, to transport to. Unused if `tangent_vec_b`
is given.
Optional, default : None.
Returns
-------
transported : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space equal to the Riemannian exponential
of tangent_vec at the base point.
"""
if direction is None:
if end_point is not None:
direction = self.log(end_point, base_point)
else:
raise ValueError(
"Either an end_point or a tangent_vec_b must be given to define the"
" geodesic along which to transport.")
max_shape = tangent_vec.shape if tangent_vec.ndim == 3 else direction.shape
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_tan_a = gs.reshape(tangent_vec, (-1, self.sphere_metric.dim + 1))
flat_tan_b = gs.reshape(direction, (-1, self.sphere_metric.dim + 1))
flat_transport = self.sphere_metric.parallel_transport(
flat_tan_a, flat_bp, flat_tan_b)
return gs.reshape(flat_transport, max_shape)
def injectivity_radius(self, base_point):
"""Compute the radius of the injectivity domain.
This is is the supremum of radii r for which the exponential map is a
diffeomorphism from the open ball of radius r centered at the base
point onto its image.
In the case of the sphere, it does not depend on the base point and is
Pi everywhere.
Parameters
----------
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the manifold.
Returns
-------
radius : float
Injectivity radius.
"""
return gs.pi
class ProcrustesMetric(RiemannianMetric):
"""Procrustes metric on the pre-shape space.
Parameters
----------
k_landmarks : int
Number of landmarks
m_ambient : int
Number of coordinates of each landmark.
"""
def __init__(self, k_landmarks, m_ambient):
super(ProcrustesMetric, self).__init__(
dim=m_ambient * (k_landmarks - 1) - 1,
default_point_type='matrix')
self.embedding_metric = MatricesMetric(k_landmarks, m_ambient)
self.sphere_metric = Hypersphere(m_ambient * k_landmarks - 1).metric
self.k_landmarks = k_landmarks
self.m_ambient = m_ambient
def inner_product(self, tangent_vec_a, tangent_vec_b, base_point=None):
"""Compute the inner-product of two tangent vectors at a base point.
Parameters
----------
tangent_vec_a : array-like, shape=[..., k_landmarks, m_ambient]
First tangent vector at base point.
tangent_vec_b : array-like, shape=[..., k_landmarks, m_ambient]
Second tangent vector at base point.
base_point : array-like, shape=[..., dk_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
inner_prod : array-like, shape=[...,]
Inner-product of the two tangent vectors.
"""
inner_prod = self.embedding_metric.inner_product(
tangent_vec_a, tangent_vec_b, base_point)
return inner_prod
def exp(self, tangent_vec, base_point):
"""Compute the Riemannian exponential of a tangent vector.
Parameters
----------
tangent_vec : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at a base point.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
exp : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space equal to the Riemannian exponential
of tangent_vec at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_tan = gs.reshape(tangent_vec, (-1, self.sphere_metric.dim + 1))
flat_exp = self.sphere_metric.exp(flat_tan, flat_bp)
return gs.reshape(flat_exp, tangent_vec.shape)
def log(self, point, base_point):
"""Compute the Riemannian logarithm of a point.
Parameters
----------
point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
log : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at the base point equal to the Riemannian logarithm
of point at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_pt = gs.reshape(point, (-1, self.sphere_metric.dim + 1))
flat_log = self.sphere_metric.log(flat_pt, flat_bp)
try:
log = gs.reshape(flat_log, base_point.shape)
except (RuntimeError,
check_tf_error(ValueError, 'InvalidArgumentError')):
log = gs.reshape(flat_log, point.shape)
return log
class PreShapeMetric(RiemannianMetric):
"""Procrustes metric on the pre-shape space.
Parameters
----------
k_landmarks : int
Number of landmarks
m_ambient : int
Number of coordinates of each landmark.
"""
def __init__(self, k_landmarks, m_ambient):
super(PreShapeMetric,
self).__init__(dim=m_ambient * (k_landmarks - 1) - 1,
default_point_type='matrix')
self.embedding_metric = MatricesMetric(k_landmarks, m_ambient)
self.sphere_metric = Hypersphere(m_ambient * k_landmarks - 1).metric
self.k_landmarks = k_landmarks
self.m_ambient = m_ambient
def inner_product(self, tangent_vec_a, tangent_vec_b, base_point=None):
"""Compute the inner-product of two tangent vectors at a base point.
Parameters
----------
tangent_vec_a : array-like, shape=[..., k_landmarks, m_ambient]
First tangent vector at base point.
tangent_vec_b : array-like, shape=[..., k_landmarks, m_ambient]
Second tangent vector at base point.
base_point : array-like, shape=[..., dk_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
inner_prod : array-like, shape=[...,]
Inner-product of the two tangent vectors.
"""
inner_prod = self.embedding_metric.inner_product(
tangent_vec_a, tangent_vec_b, base_point)
return inner_prod
def exp(self, tangent_vec, base_point):
"""Compute the Riemannian exponential of a tangent vector.
Parameters
----------
tangent_vec : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at a base point.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
exp : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space equal to the Riemannian exponential
of tangent_vec at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_tan = gs.reshape(tangent_vec, (-1, self.sphere_metric.dim + 1))
flat_exp = self.sphere_metric.exp(flat_tan, flat_bp)
return gs.reshape(flat_exp, tangent_vec.shape)
def log(self, point, base_point):
"""Compute the Riemannian logarithm of a point.
Parameters
----------
point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
base_point : array-like, shape=[..., k_landmarks, m_ambient]
Point on the pre-shape space.
Returns
-------
log : array-like, shape=[..., k_landmarks, m_ambient]
Tangent vector at the base point equal to the Riemannian logarithm
of point at the base point.
"""
flat_bp = gs.reshape(base_point, (-1, self.sphere_metric.dim + 1))
flat_pt = gs.reshape(point, (-1, self.sphere_metric.dim + 1))
flat_log = self.sphere_metric.log(flat_pt, flat_bp)
try:
log = gs.reshape(flat_log, base_point.shape)
except (RuntimeError, check_tf_error(ValueError,
'InvalidArgumentError')):
log = gs.reshape(flat_log, point.shape)
return log
def curvature(self, tangent_vec_a, tangent_vec_b, tangent_vec_c,
base_point):
r"""Compute the curvature.
For three tangent vectors at a base point :math: `x,y,z`,
the curvature is defined by
:math: `R(X, Y)Z = \nabla_{[X,Y]}Z
- \nabla_X\nabla_Y Z + - \nabla_Y\nabla_X Z`, where :math: `\nabla`
is the Levi-Civita connection. In the case of the hypersphere,
we have the closed formula
:math: `R(X,Y)Z = \langle X, Z \rangle Y - \langle Y,Z \rangle X`.
Parameters
----------
tangent_vec_a : array-like, shape=[..., n, n]
Tangent vector at `base_point`.
tangent_vec_b : array-like, shape=[..., n, n]
Tangent vector at `base_point`.
tangent_vec_c : array-like, shape=[..., n, n]
Tangent vector at `base_point`.
base_point : array-like, shape=[..., n, n]
Point on the group. Optional, default is the identity.
Returns
-------
curvature : array-like, shape=[..., n, n]
Tangent vector at `base_point`.
"""
max_shape = base_point.shape
for arg in [tangent_vec_a, tangent_vec_b, tangent_vec_c]:
if arg.ndim >= 3:
max_shape = arg.shape
flat_shape = (-1, self.sphere_metric.dim + 1)
flat_a = gs.reshape(tangent_vec_a, flat_shape)
flat_b = gs.reshape(tangent_vec_b, flat_shape)
flat_c = gs.reshape(tangent_vec_c, flat_shape)
flat_bp = gs.reshape(base_point, flat_shape)
curvature = self.sphere_metric.curvature(flat_a, flat_b, flat_c,
flat_bp)
curvature = gs.reshape(curvature, max_shape)
return curvature
def __init__(self, nodes):
self.total_space_metric = MatricesMetric(nodes, nodes)
self.nodes = nodes
self.space = _GraphSpace(nodes)
class GraphSpaceMetric:
"""Quotient metric on the graph space.
Parameters
----------
nodes : int
Number of nodes
"""
def __init__(self, nodes):
self.total_space_metric = MatricesMetric(nodes, nodes)
self.nodes = nodes
self.space = _GraphSpace(nodes)
def dist(self, base_graph, graph_to_permute, matcher="ID"):
"""Compute distance between two equivalence classes.
Compute the distance between two equivalence classes of
adjacency matrices [Jain2009]_.
Parameters
----------
base_graph : array-like, shape=[..., n, n]
First graph.
graph_to_permute : array-like, shape=[..., n, n]
Second graph to align to the first graph.
matcher : selecting which matcher to use
'FAQ': [Vogelstein2015]_ Fast Quadratic Assignment
note: use Frobenius metric in background.
Returns
-------
distance : array-like, shape=[...,]
distance between equivalence classes.
References
----------
..[Jain2009] Jain, B., Obermayer, K.
"Structure Spaces." Journal of Machine Learning Research 10.11 (2009).
https://www.jmlr.org/papers/v10/jain09a.html.
..[Vogelstein2015] Vogelstein JT, Conroy JM, Lyzinski V, Podrazik LJ,
Kratzer SG, Harley ET, Fishkind DE, Vogelstein RJ, Priebe CE.
“Fast approximate quadratic programming for graph matching.“
PLoS One. 2015 Apr 17; doi: 10.1371/journal.pone.0121002.
"""
if matcher == "FAQ":
perm = self.faq_matching(base_graph, graph_to_permute)
if matcher == "ID":
perm = self.id_matching(base_graph, graph_to_permute)
return self.total_space_metric.dist(
base_graph,
self.space.permute(graph_to_permute=graph_to_permute,
permutation=perm),
)
@staticmethod
def faq_matching(base_graph, graph_to_permute):
"""Fast Quadratic Assignment for graph matching.
Parameters
----------
base_graph : array-like, shape=[..., n, n]
First graph.
graph_to_permute : array-like, shape=[..., n, n]
Second graph to align.
Returns
-------
permutation : array-like, shape=[...,n]
node permutation indexes of the second graph.
References
----------
..[Vogelstein2015] Vogelstein JT, Conroy JM, Lyzinski V, Podrazik LJ,
Kratzer SG, Harley ET, Fishkind DE, Vogelstein RJ, Priebe CE.
“Fast approximate quadratic programming for graph matching.“
PLoS One. 2015 Apr 17; doi: 10.1371/journal.pone.0121002.
"""
l_base = len(base_graph.shape)
l_obj = len(graph_to_permute.shape)
if l_base == l_obj == 3:
return [
gs.linalg.quadratic_assignment(x,
y,
options={"maximize": True})
for x, y in zip(base_graph, graph_to_permute)
]
if l_base == l_obj == 2:
return gs.linalg.quadratic_assignment(base_graph,
graph_to_permute,
options={"maximize": True})
if l_base < l_obj:
return [
gs.linalg.quadratic_assignment(x,
y,
options={"maximize": True})
for x, y in zip(
gs.stack([base_graph] *
graph_to_permute.shape[0]), graph_to_permute)
]
raise ValueError(
"The method can align a set of graphs to one graphs,"
"but the single graphs should be passed as base_graph")
def id_matching(self, base_graph, graph_to_permute):
"""Identity matching.
Parameters
----------
base_graph : array-like, shape=[..., n, n]
First graph.
graph_to_permute : array-like, shape=[..., n, n]
Second graph to align.
Returns
-------
permutation : array-like, shape=[...,n]
node permutation indexes of the second graph.
"""
l_base = len(base_graph.shape)
l_obj = len(graph_to_permute.shape)
if l_base == l_obj == 3 or l_base < l_obj:
return [list(range(self.nodes))] * len(graph_to_permute)
if l_base == l_obj == 2:
return list(range(self.nodes))
raise (ValueError(
"The method can align a set of graphs to one graphs,"
"but the single graphs should be passed as base_graph"))
