Unverified Commit 69f5869f authored by Tianjun Xiao's avatar Tianjun Xiao Committed by GitHub
Browse files

[Doc] NN doc refactor Conv Layers (#1672)



* go through gcn, relgcn

* fix tagconv formula

* fix doc in sageconv

* fix sgconv doc

* replace hat with tilde

* more comments on gmmconv

* fix agnnconv chebconv doc

* modify nnconv doc

* remove &

* add nn conv examples

* Rebase master

* More merge conflicts

* check homo

* add back self loop for some convs, check homo in tranform

* add example for denseconv

* add example and doc for dotgat and cfconv

* check in-degree for graphconv

* add language fix

* gconv address all comments

* another round of change based on api template

* change agnn

* go through agnn, appnp, atomic, cf, cheb, dense, gat, sage modules

* finish pytorch part of nn conv

* mxnet graphconv done

* tensorflow graphconv works

* add new modules into doc

* add comments to not split code

* refine doc

* resr

* more comments

* more fix

* finish conv and dense conv part api

* pylint fix

* fix pylink

* fix pylint

* more fix

* fix

* fix test fail because zere in degree

* fix test fail

* sage is not update for mxnet tf
Co-authored-by: default avatarUbuntu <ubuntu@ip-172-31-0-81.us-east-2.compute.internal>
parent 98c1117d
......@@ -122,6 +122,21 @@ AtomicConv
:members: forward
:show-inheritance:
CFConv
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. autoclass:: dgl.nn.pytorch.conv.CFConv
:members: forward
:show-inheritance:
DotGatConv
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. autoclass:: dgl.nn.pytorch.conv.DotGatConv
:members: forward
:show-inheritance:
Dense Conv Layers
----------------------------------------
......
......@@ -10,40 +10,27 @@ from ....base import DGLError
from ....utils import expand_as_pair
class GraphConv(gluon.Block):
r"""Apply graph convolution over an input signal.
r"""
Graph convolution is introduced in `GCN <https://arxiv.org/abs/1609.02907>`__
and can be described as below:
Description
-----------
Graph convolution was introduced in `GCN <https://arxiv.org/abs/1609.02907>`__
and mathematically is defined as follows:
.. math::
h_i^{(l+1)} = \sigma(b^{(l)} + \sum_{j\in\mathcal{N}(i)}\frac{1}{c_{ij}}h_j^{(l)}W^{(l)})
where :math:`\mathcal{N}(i)` is the neighbor set of node :math:`i`. :math:`c_{ij}` is equal
to the product of the square root of node degrees:
:math:`\sqrt{|\mathcal{N}(i)|}\sqrt{|\mathcal{N}(j)|}`. :math:`\sigma` is an activation
function.
The model parameters are initialized as in the
`original implementation <https://github.com/tkipf/gcn/blob/master/gcn/layers.py>`__ where
the weight :math:`W^{(l)}` is initialized using Glorot uniform initialization
and the bias is initialized to be zero.
Notes
-----
Zero in degree nodes could lead to invalid normalizer. A common practice
to avoid this is to add a self-loop for each node in the graph, which
can be achieved by:
>>> g = ... # some DGLGraph
>>> g.add_edges(g.nodes(), g.nodes())
where :math:`\mathcal{N}(i)` is the set of neighbors of node :math:`i`,
:math:`c_{ij}` is the product of the square root of node degrees
(i.e., :math:`c_{ij} = \sqrt{|\mathcal{N}(i)|}\sqrt{|\mathcal{N}(j)|}`),
and :math:`\sigma` is an activation function.
Parameters
----------
in_feats : int
Number of input features.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
out_feats : int
Number of output features.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
norm : str, optional
How to apply the normalizer. If is `'right'`, divide the aggregated messages
by each node's in-degrees, which is equivalent to averaging the received messages.
......@@ -54,16 +41,91 @@ class GraphConv(gluon.Block):
without a weight matrix.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
activation: callable activation function/layer or None, optional
activation : callable activation function/layer or None, optional
If not None, applies an activation function to the updated node features.
Default: ``None``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Attributes
----------
weight : mxnet.gluon.parameter.Parameter
weight : torch.Tensor
The learnable weight tensor.
bias : mxnet.gluon.parameter.Parameter
bias : torch.Tensor
The learnable bias tensor.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import mxnet as mx
>>> from mxnet import gluon
>>> import numpy as np
>>> from dgl.nn import GraphConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = mx.nd.ones((6, 10))
>>> conv = GraphConv(10, 2, norm='both', weight=True, bias=True)
>>> conv.initialize(ctx=mx.cpu(0))
>>> res = conv(g, feat)
>>> print(res)
[[1.0209361 0.22472616]
[1.1240715 0.24742813]
[1.0209361 0.22472616]
[1.2924911 0.28450024]
[1.3568745 0.29867214]
[0.7948386 0.17495811]]
<NDArray 6x2 @cpu(0)>
>>> # allow_zero_in_degree example
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> conv = GraphConv(10, 2, norm='both', weight=True, bias=True, allow_zero_in_degree=True)
>>> res = conv(g, feat)
>>> print(res)
[[1.0209361 0.22472616]
[1.1240715 0.24742813]
[1.0209361 0.22472616]
[1.2924911 0.28450024]
[1.3568745 0.29867214]
[0. 0.]]
<NDArray 6x2 @cpu(0)>
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_fea = mx.nd.random.randn(2, 5)
>>> v_fea = mx.nd.random.randn(4, 5)
>>> conv = GraphConv(5, 2, norm='both', weight=True, bias=True)
>>> conv.initialize(ctx=mx.cpu(0))
>>> res = conv(g, (u_fea, v_fea))
>>> res
[[ 0.26967263 0.308129 ]
[ 0.05143356 -0.11355402]
[ 0.22705637 0.1375853 ]
[ 0.26967263 0.308129 ]]
<NDArray 4x2 @cpu(0)>
"""
def __init__(self,
in_feats,
......@@ -71,7 +133,8 @@ class GraphConv(gluon.Block):
norm='both',
weight=True,
bias=True,
activation=None):
activation=None,
allow_zero_in_degree=False):
super(GraphConv, self).__init__()
if norm not in ('none', 'both', 'right'):
raise DGLError('Invalid norm value. Must be either "none", "both" or "right".'
......@@ -79,6 +142,7 @@ class GraphConv(gluon.Block):
self._in_feats = in_feats
self._out_feats = out_feats
self._norm = norm
self._allow_zero_in_degree = allow_zero_in_degree
with self.name_scope():
if weight:
......@@ -96,15 +160,11 @@ class GraphConv(gluon.Block):
self._activation = activation
def forward(self, graph, feat, weight=None):
r"""Compute graph convolution.
r"""
Notes
-----
* Input shape: :math:`(N, *, \text{in_feats})` where * means any number of additional
dimensions, :math:`N` is the number of nodes.
* Output shape: :math:`(N, *, \text{out_feats})` where all but the last dimension are
the same shape as the input.
* Weight shape: :math:`(\text{in_feats}, \text{out_feats})`.
Description
-----------
Compute graph convolution.
Parameters
----------
......@@ -126,8 +186,35 @@ class GraphConv(gluon.Block):
-------
mxnet.NDArray
The output feature
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
Notes
-----
* Input shape: :math:`(N, *, \text{in_feats})` where * means any number of additional
dimensions, :math:`N` is the number of nodes.
* Output shape: :math:`(N, *, \text{out_feats})` where all but the last dimension are
the same shape as the input.
* Weight shape: :math:`(\text{in_feats}, \text{out_feats})`.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).asnumpy().any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
feat_src, feat_dst = expand_as_pair(feat, graph)
if self._norm == 'both':
......
......@@ -20,8 +20,9 @@ from .densegraphconv import DenseGraphConv
from .densesageconv import DenseSAGEConv
from .atomicconv import AtomicConv
from .cfconv import CFConv
from .dotgatconv import DotGatConv
__all__ = ['GraphConv', 'GATConv', 'TAGConv', 'RelGraphConv', 'SAGEConv',
'SGConv', 'APPNPConv', 'GINConv', 'GatedGraphConv', 'GMMConv',
'ChebConv', 'AGNNConv', 'NNConv', 'DenseGraphConv', 'DenseSAGEConv',
'DenseChebConv', 'EdgeConv', 'AtomicConv', 'CFConv']
'DenseChebConv', 'EdgeConv', 'AtomicConv', 'CFConv', 'DotGatConv']
......@@ -6,11 +6,16 @@ from torch.nn import functional as F
from .... import function as fn
from ....ops import edge_softmax
from ....base import DGLError
from ....utils import expand_as_pair
class AGNNConv(nn.Module):
r"""Attention-based Graph Neural Network layer from paper `Attention-based
r"""
Description
-----------
Attention-based Graph Neural Network layer from paper `Attention-based
Graph Neural Network for Semi-Supervised Learning
<https://arxiv.org/abs/1803.03735>`__.
......@@ -22,24 +27,75 @@ class AGNNConv(nn.Module):
.. math::
P_{ij} = \mathrm{softmax}_i ( \beta \cdot \cos(h_i^l, h_j^l))
where :math:`\beta` is a single scalar parameter.
Parameters
----------
init_beta : float, optional
The :math:`\beta` in the formula.
The :math:`\beta` in the formula, a single scalar parameter.
learn_beta : bool, optional
If True, :math:`\beta` will be learnable parameter.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import AGNNConv
>>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> conv = AGNNConv()
>>> res = conv(g, feat)
>>> res
tensor([[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.],
[1., 1., 1., 1., 1., 1., 1., 1., 1., 1.]],
grad_fn=<BinaryReduceBackward>)
"""
def __init__(self,
init_beta=1.,
learn_beta=True):
learn_beta=True,
allow_zero_in_degree=False):
super(AGNNConv, self).__init__()
self._allow_zero_in_degree = allow_zero_in_degree
if learn_beta:
self.beta = nn.Parameter(th.Tensor([init_beta]))
else:
self.register_buffer('beta', th.Tensor([init_beta]))
def forward(self, graph, feat):
r"""Compute AGNN layer.
r"""
Description
-----------
Compute AGNN layer.
Parameters
----------
......@@ -49,7 +105,7 @@ class AGNNConv(nn.Module):
The input feature of shape :math:`(N, *)` :math:`N` is the
number of nodes, and :math:`*` could be of any shape.
If a pair of torch.Tensor is given, the pair must contain two tensors of shape
:math:`(N_{in}, *)` and :math:`(N_{out}, *})`, the the :math:`*` in the later
:math:`(N_{in}, *)` and :math:`(N_{out}, *)`, the :math:`*` in the later
tensor must equal the previous one.
Returns
......@@ -57,9 +113,29 @@ class AGNNConv(nn.Module):
torch.Tensor
The output feature of shape :math:`(N, *)` where :math:`*`
should be the same as input shape.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
feat_src, feat_dst = expand_as_pair(feat, graph)
graph.srcdata['h'] = feat_src
graph.srcdata['norm_h'] = F.normalize(feat_src, p=2, dim=-1)
if isinstance(feat, tuple) or graph.is_block:
......
......@@ -5,27 +5,57 @@ from torch import nn
from .... import function as fn
class APPNPConv(nn.Module):
r"""Approximate Personalized Propagation of Neural Predictions
r"""
Description
-----------
Approximate Personalized Propagation of Neural Predictions
layer from paper `Predict then Propagate: Graph Neural Networks
meet Personalized PageRank <https://arxiv.org/pdf/1810.05997.pdf>`__.
.. math::
H^{0} & = X
H^{0} &= X
H^{l+1} &= (1-\alpha)\left(\tilde{D}^{-1/2}
\tilde{A} \tilde{D}^{-1/2} H^{l}\right) + \alpha H^{0}
H^{t+1} & = (1-\alpha)\left(\hat{D}^{-1/2}
\hat{A} \hat{D}^{-1/2} H^{t}\right) + \alpha H^{0}
where :math:`\tilde{A}` is :math:`A` + :math:`I`.
Parameters
----------
k : int
Number of iterations :math:`K`.
The number of iterations :math:`K`.
alpha : float
The teleport probability :math:`\alpha`.
edge_drop : float, optional
Dropout rate on edges that controls the
The dropout rate on edges that controls the
messages received by each node. Default: ``0``.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import APPNPConv
>>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> feat = th.ones(6, 10)
>>> conv = APPNPConv(k=3, alpha=0.5)
>>> res = conv(g, feat)
>>> res
tensor([[1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000,
1.0000],
[1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000,
1.0000],
[1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000, 1.0000,
1.0000],
[1.0303, 1.0303, 1.0303, 1.0303, 1.0303, 1.0303, 1.0303, 1.0303, 1.0303,
1.0303],
[0.8643, 0.8643, 0.8643, 0.8643, 0.8643, 0.8643, 0.8643, 0.8643, 0.8643,
0.8643],
[0.5000, 0.5000, 0.5000, 0.5000, 0.5000, 0.5000, 0.5000, 0.5000, 0.5000,
0.5000]])
"""
def __init__(self,
k,
......@@ -37,14 +67,18 @@ class APPNPConv(nn.Module):
self.edge_drop = nn.Dropout(edge_drop)
def forward(self, graph, feat):
r"""Compute APPNP layer.
r"""
Description
-----------
Compute APPNP layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, *)` :math:`N` is the
The input feature of shape :math:`(N, *)`. :math:`N` is the
number of nodes, and :math:`*` could be of any shape.
Returns
......
......@@ -5,7 +5,11 @@ import torch as th
import torch.nn as nn
class RadialPooling(nn.Module):
r"""Radial pooling from paper `Atomic Convolutional Networks for
r"""
Description
-----------
Radial pooling from paper `Atomic Convolutional Networks for
Predicting Protein-Ligand Binding Affinity <https://arxiv.org/abs/1703.10603>`__.
We denote the distance between atom :math:`i` and :math:`j` by :math:`r_{ij}`.
......@@ -53,7 +57,11 @@ class RadialPooling(nn.Module):
rbf_kernel_scaling.reshape(-1, 1, 1), requires_grad=True)
def forward(self, distances):
"""Apply the layer to transform edge distances.
"""
Description
-----------
Apply the layer to transform edge distances.
Parameters
----------
......@@ -81,7 +89,11 @@ class RadialPooling(nn.Module):
return rbf_kernel_results * cutoff_values
def msg_func(edges):
"""Send messages along edges.
"""
Description
-----------
Send messages along edges.
Parameters
----------
......@@ -99,7 +111,11 @@ def msg_func(edges):
'ij,ik->ijk', edges.src['hv'], edges.data['he']).view(len(edges), -1)}
def reduce_func(nodes):
"""Collect messages and update node representations.
"""
Description
-----------
Collect messages and update node representations.
Parameters
----------
......@@ -116,10 +132,14 @@ def reduce_func(nodes):
return {'hv_new': nodes.mailbox['m'].sum(1)}
class AtomicConv(nn.Module):
r"""Atomic Convolution Layer from paper `Atomic Convolutional Networks for
r"""
Description
-----------
Atomic Convolution Layer from paper `Atomic Convolutional Networks for
Predicting Protein-Ligand Binding Affinity <https://arxiv.org/abs/1703.10603>`__.
We denote the type of atom :math:`i` by :math:`z_i` and the distance between atom
Denoting the type of atom :math:`i` by :math:`z_i` and the distance between atom
:math:`i` and :math:`j` by :math:`r_{ij}`.
**Distance Transformation**
......@@ -155,20 +175,7 @@ class AtomicConv(nn.Module):
.. math::
p_{i, t}^{k} = \sum_{j\in N(i)} e_{ij}^{k} * 1(z_j == t)
We concatenate the results for all RBF kernels and atom types.
Notes
-----
* This convolution operation is designed for molecular graphs in Chemistry, but it might
be possible to extend it to more general graphs.
* There seems to be an inconsistency about the definition of :math:`e_{ij}^{k}` in the
paper and the author's implementation. We follow the author's implementation. In the
paper, :math:`e_{ij}^{k}` was defined as
:math:`\exp(-\gamma_{k}|r_{ij}-r_{k}|^2 * f_{ij}^{k})`.
* :math:`\gamma_{k}`, :math:`r_k` and :math:`c_k` are all learnable.
Then concatenate the results for all RBF kernels and atom types.
Parameters
----------
......@@ -183,6 +190,42 @@ class AtomicConv(nn.Module):
features_to_use : None or float tensor of shape (T)
In the original paper, these are atomic numbers to consider, representing the types
of atoms. T for the number of types of atomic numbers. Default to None.
Notes
-----
* This convolution operation is designed for molecular graphs in Chemistry, but it might
be possible to extend it to more general graphs.
* There seems to be an inconsistency about the definition of :math:`e_{ij}^{k}` in the
paper and the author's implementation. We follow the author's implementation. In the
paper, :math:`e_{ij}^{k}` was defined as
:math:`\exp(-\gamma_{k}|r_{ij}-r_{k}|^2 * f_{ij}^{k})`.
* :math:`\gamma_{k}`, :math:`r_k` and :math:`c_k` are all learnable.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import AtomicConv
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> feat = th.ones(6, 1)
>>> edist = th.ones(6, 1)
>>> interaction_cutoffs = th.ones(3).float() * 2
>>> rbf_kernel_means = th.ones(3).float()
>>> rbf_kernel_scaling = th.ones(3).float()
>>> conv = AtomicConv(interaction_cutoffs, rbf_kernel_means, rbf_kernel_scaling)
>>> res = conv(g, feat, edist)
>>> res
tensor([[0.5000, 0.5000, 0.5000],
[0.5000, 0.5000, 0.5000],
[0.5000, 0.5000, 0.5000],
[1.0000, 1.0000, 1.0000],
[0.5000, 0.5000, 0.5000],
[0.0000, 0.0000, 0.0000]], grad_fn=<ViewBackward>)
"""
def __init__(self, interaction_cutoffs, rbf_kernel_means,
rbf_kernel_scaling, features_to_use=None):
......@@ -199,23 +242,27 @@ class AtomicConv(nn.Module):
self.features_to_use = nn.Parameter(features_to_use, requires_grad=False)
def forward(self, graph, feat, distances):
"""Apply the atomic convolution layer.
"""
Description
-----------
Apply the atomic convolution layer.
Parameters
----------
graph : DGLGraph
Topology based on which message passing is performed.
feat : Float32 tensor of shape (V, 1)
feat : Float32 tensor of shape :math:`(V, 1)`
Initial node features, which are atomic numbers in the paper.
V for the number of nodes.
distances : Float32 tensor of shape (E, 1)
:math:`V` for the number of nodes.
distances : Float32 tensor of shape :math:`(E, 1)`
Distance between end nodes of edges. E for the number of edges.
Returns
-------
Float32 tensor of shape (V, K * T)
Updated node representations. V for the number of nodes, K for the
number of radial filters, and T for the number of types of atomic numbers.
Float32 tensor of shape :math:`(V, K * T)`
Updated node representations. :math:`V` for the number of nodes, :math:`K` for the
number of radial filters, and :math:`T` for the number of types of atomic numbers.
"""
with graph.local_scope():
radial_pooled_values = self.radial_pooling(distances) # (K, E, 1)
......
......@@ -6,12 +6,16 @@ import torch.nn as nn
from .... import function as fn
class ShiftedSoftplus(nn.Module):
r"""Applies the element-wise function:
r"""
Description
-----------
Applies the element-wise function:
.. math::
\text{SSP}(x) = \frac{1}{\beta} * \log(1 + \exp(\beta * x)) - \log(\text{shift})
Parameters
Attributes
----------
beta : int
:math:`\beta` value for the mathematical formulation. Default to 1.
......@@ -25,7 +29,11 @@ class ShiftedSoftplus(nn.Module):
self.softplus = nn.Softplus(beta=beta, threshold=threshold)
def forward(self, inputs):
"""Applies the activation function.
"""
Description
-----------
Applies the activation function.
Parameters
----------
......@@ -40,23 +48,54 @@ class ShiftedSoftplus(nn.Module):
return self.softplus(inputs) - np.log(float(self.shift))
class CFConv(nn.Module):
r"""CFConv in SchNet.
r"""
Description
-----------
CFConv in SchNet.
SchNet is introduced in `SchNet: A continuous-filter convolutional neural network for
modeling quantum interactions <https://arxiv.org/abs/1706.08566>`__.
It combines node and edge features in message passing and updates node representations.
.. math::
h_i^{(l+1)} = \sum_{j\in \mathcal{N}(i)} h_j^{l} \circ W^{(l)}e_ij
where :math:`\circ` represents element-wise multiplication and for :math:`\text{SPP}` :
.. math::
\text{SSP}(x) = \frac{1}{\beta} * \log(1 + \exp(\beta * x)) - \log(\text{shift})
Parameters
----------
node_in_feats : int
Size for the input node features.
Size for the input node features :math:`h_j^{(l)}`.
edge_in_feats : int
Size for the input edge features.
Size for the input edge features :math:`e_ij`.
hidden_feats : int
Size for the hidden representations.
out_feats : int
Size for the output representations.
Size for the output representations :math:`h_j^{(l+1)}`.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import CFConv
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> nfeat = th.ones(6, 10)
>>> efeat = th.ones(6, 5)
>>> conv = CFConv(10, 5, 3, 2)
>>> res = conv(g, nfeat, efeat)
>>> res
tensor([[-0.1209, -0.2289],
[-0.1209, -0.2289],
[-0.1209, -0.2289],
[-0.1135, -0.2338],
[-0.1209, -0.2289],
[-0.1283, -0.2240]], grad_fn=<SubBackward0>)
"""
def __init__(self, node_in_feats, edge_in_feats, hidden_feats, out_feats):
super(CFConv, self).__init__()
......@@ -74,7 +113,11 @@ class CFConv(nn.Module):
)
def forward(self, g, node_feats, edge_feats):
"""Performs message passing and updates node representations.
"""
Description
-----------
Performs message passing and updates node representations.
Parameters
----------
......
......@@ -9,7 +9,11 @@ from .... import laplacian_lambda_max, broadcast_nodes, function as fn
class ChebConv(nn.Module):
r"""Chebyshev Spectral Graph Convolution layer from paper `Convolutional
r"""
Description
-----------
Chebyshev Spectral Graph Convolution layer from paper `Convolutional
Neural Networks on Graphs with Fast Localized Spectral Filtering
<https://arxiv.org/pdf/1606.09375.pdf>`__.
......@@ -18,24 +22,50 @@ class ChebConv(nn.Module):
Z^{0, l} &= H^{l}
Z^{1, l} &= \hat{L} \cdot H^{l}
Z^{1, l} &= \tilde{L} \cdot H^{l}
Z^{k, l} &= 2 \cdot \tilde{L} \cdot Z^{k-1, l} - Z^{k-2, l}
Z^{k, l} &= 2 \cdot \hat{L} \cdot Z^{k-1, l} - Z^{k-2, l}
\tilde{L} &= 2\left(I - \tilde{D}^{-1/2} \tilde{A} \tilde{D}^{-1/2}\right)/\lambda_{max} - I
where :math:`\tilde{A}` is :math:`A` + :math:`I`, :math:`W` is learnable weight.
\hat{L} &= 2\left(I - \hat{D}^{-1/2} \hat{A} \hat{D}^{-1/2}\right)/\lambda_{max} - I
Parameters
----------
in_feats: int
Number of input features.
Dimension of input features; i.e, the number of dimensions of :math:`h_i^{(l)}`.
out_feats: int
Number of output features.
Dimension of output features :math:`h_i^{(l+1)}`.
k : int
Chebyshev filter size.
Chebyshev filter size :math:`K`.
activation : function, optional
Activation function, default is ReLu.
Activation function. Default ``ReLu``.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
Note
----
ChebConv only support DGLGraph as input for now. Heterograph will report error. To be fixed.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import ChebConv
>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> feat = th.ones(6, 10)
>>> conv = ChebConv(10, 2, 2)
>>> res = conv(g, feat)
>>> res
tensor([[ 0.6163, -0.1809],
[ 0.6163, -0.1809],
[ 0.6163, -0.1809],
[ 0.9698, -1.5053],
[ 0.3664, 0.7556],
[-0.2370, 3.0164]], grad_fn=<AddBackward0>)
"""
def __init__(self,
......@@ -52,7 +82,11 @@ class ChebConv(nn.Module):
self.linear = nn.Linear(k * in_feats, out_feats, bias)
def forward(self, graph, feat, lambda_max=None):
r"""Compute ChebNet layer.
r"""
Description
-----------
Compute ChebNet layer.
Parameters
----------
......
......@@ -6,7 +6,11 @@ from torch.nn import init
class DenseChebConv(nn.Module):
r"""Chebyshev Spectral Graph Convolution layer from paper `Convolutional
r"""
Description
-----------
Chebyshev Spectral Graph Convolution layer from paper `Convolutional
Neural Networks on Graphs with Fast Localized Spectral Filtering
<https://arxiv.org/pdf/1606.09375.pdf>`__.
......@@ -15,17 +19,43 @@ class DenseChebConv(nn.Module):
Parameters
----------
in_feats: int
Number of input features.
Dimension of input features :math:`h_i^{(l)}`.
out_feats: int
Number of output features.
Dimension of output features :math:`h_i^{(l+1)}`.
k : int
Chebyshev filter size.
activation : function, optional
Activation function, default is ReLu.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import DenseChebConv
>>>
>>> feat = th.ones(6, 10)
>>> adj = th.tensor([[0., 0., 1., 0., 0., 0.],
... [1., 0., 0., 0., 0., 0.],
... [0., 1., 0., 0., 0., 0.],
... [0., 0., 1., 0., 0., 1.],
... [0., 0., 0., 1., 0., 0.],
... [0., 0., 0., 0., 0., 0.]])
>>> conv = DenseChebConv(10, 2, 2)
>>> res = conv(adj, feat)
>>> res
tensor([[-3.3516, -2.4797],
[-3.3516, -2.4797],
[-3.3516, -2.4797],
[-4.5192, -3.0835],
[-2.5259, -2.0527],
[-0.5327, -1.0219]], grad_fn=<AddBackward0>)
See also
--------
ChebConv
`ChebConv <https://docs.dgl.ai/api/python/nn.pytorch.html#chebconv>`__
"""
def __init__(self,
in_feats,
......@@ -51,7 +81,11 @@ class DenseChebConv(nn.Module):
init.xavier_normal_(self.W[i], init.calculate_gain('relu'))
def forward(self, adj, feat, lambda_max=None):
r"""Compute (Dense) Chebyshev Spectral Graph Convolution layer.
r"""
Description
-----------
Compute (Dense) Chebyshev Spectral Graph Convolution layer.
Parameters
----------
......
......@@ -6,7 +6,11 @@ from torch.nn import init
class DenseGraphConv(nn.Module):
"""Graph Convolutional Network layer where the graph structure
"""
Description
-----------
Graph Convolutional Network layer where the graph structure
is given by an adjacency matrix.
We recommend user to use this module when applying graph convolution on
dense graphs.
......@@ -14,23 +18,53 @@ class DenseGraphConv(nn.Module):
Parameters
----------
in_feats : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
out_feats : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
norm : str, optional
How to apply the normalizer. If is `'right'`, divide the aggregated messages
by each node's in-degrees, which is equivalent to averaging the received messages.
If is `'none'`, no normalization is applied. Default is `'both'`,
where the :math:`c_{ij}` in the paper is applied.
bias : bool
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
activation : callable activation function/layer or None, optional
If not None, applies an activation function to the updated node features.
Default: ``None``.
Notes
-----
Zero in-degree nodes will lead to all-zero output. A common practice
to avoid this is to add a self-loop for each node in the graph,
which can be achieved by setting the diagonal of the adjacency matrix to be 1.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import DenseGraphConv
>>>
>>> feat = th.ones(6, 10)
>>> adj = th.tensor([[0., 0., 1., 0., 0., 0.],
... [1., 0., 0., 0., 0., 0.],
... [0., 1., 0., 0., 0., 0.],
... [0., 0., 1., 0., 0., 1.],
... [0., 0., 0., 1., 0., 0.],
... [0., 0., 0., 0., 0., 0.]])
>>> conv = DenseGraphConv(10, 2)
>>> res = conv(adj, feat)
>>> res
tensor([[0.2159, 1.9027],
[0.3053, 2.6908],
[0.3053, 2.6908],
[0.3685, 3.2481],
[0.3053, 2.6908],
[0.0000, 0.0000]], grad_fn=<AddBackward0>)
See also
--------
GraphConv
`GraphConv <https://docs.dgl.ai/api/python/nn.pytorch.html#graphconv>`__
"""
def __init__(self,
in_feats,
......@@ -58,7 +92,11 @@ class DenseGraphConv(nn.Module):
init.zeros_(self.bias)
def forward(self, adj, feat):
r"""Compute (Dense) Graph Convolution layer.
r"""
Description
-----------
Compute (Dense) Graph Convolution layer.
Parameters
----------
......
......@@ -5,7 +5,11 @@ from ....utils import check_eq_shape
class DenseSAGEConv(nn.Module):
"""GraphSAGE layer where the graph structure is given by an
"""
Description
-----------
GraphSAGE layer where the graph structure is given by an
adjacency matrix.
We recommend to use this module when appying GraphSAGE on dense graphs.
......@@ -14,9 +18,9 @@ class DenseSAGEConv(nn.Module):
Parameters
----------
in_feats : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_i^{(l)}`.
out_feats : int
Output feature size.
Output feature size; i.e, the number of dimensions of :math:`h_i^{(l+1)}`.
feat_drop : float, optional
Dropout rate on features. Default: 0.
bias : bool
......@@ -27,9 +31,33 @@ class DenseSAGEConv(nn.Module):
If not None, applies an activation function to the updated node features.
Default: ``None``.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import DenseSAGEConv
>>>
>>> feat = th.ones(6, 10)
>>> adj = th.tensor([[0., 0., 1., 0., 0., 0.],
... [1., 0., 0., 0., 0., 0.],
... [0., 1., 0., 0., 0., 0.],
... [0., 0., 1., 0., 0., 1.],
... [0., 0., 0., 1., 0., 0.],
... [0., 0., 0., 0., 0., 0.]])
>>> conv = DenseSAGEConv(10, 2)
>>> res = conv(adj, feat)
>>> res
tensor([[1.0401, 2.1008],
[1.0401, 2.1008],
[1.0401, 2.1008],
[1.0401, 2.1008],
[1.0401, 2.1008],
[1.0401, 2.1008]], grad_fn=<AddmmBackward>)
See also
--------
SAGEConv
`SAGEConv <https://docs.dgl.ai/api/python/nn.pytorch.html#sageconv>`__
"""
def __init__(self,
in_feats,
......@@ -48,12 +76,25 @@ class DenseSAGEConv(nn.Module):
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
r"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The linear weights :math:`W^{(l)}` are initialized using Glorot uniform initialization.
"""
gain = nn.init.calculate_gain('relu')
nn.init.xavier_uniform_(self.fc.weight, gain=gain)
def forward(self, adj, feat):
r"""Compute (Dense) Graph SAGE layer.
r"""
Description
-----------
Compute (Dense) Graph SAGE layer.
Parameters
----------
......
......@@ -4,11 +4,16 @@ from torch import nn
from .... import function as fn
from ....ops import edge_softmax
from ....base import DGLError
from ....utils import expand_as_pair
class DotGatConv(nn.Module):
r"""Apply dot product version of self attention in GCN.
r"""
Description
-----------
Apply dot product version of self attention in GCN.
.. math::
h_i^{(l+1)} = \sum_{j\in \mathcal{N}(i)} \alpha_{i, j} h_j^{(l)}
......@@ -16,22 +21,92 @@ class DotGatConv(nn.Module):
where :math:`\alpha_{ij}` is the attention score bewteen node :math:`i` and node :math:`j`:
.. math::
\alpha_{i, j} = \mathrm{softmax_i}(e_{ij}^{l})
\alpha_{i, j} &= \mathrm{softmax_i}(e_{ij}^{l})
e_{ij}^{l} = ({W_i^{(l)} h_i^{(l)}})^T \cdot {W_j^{(l)} h_j^{(l)}}
e_{ij}^{l} &= ({W_i^{(l)} h_i^{(l)}})^T \cdot {W_j^{(l)} h_j^{(l)}}
where :math:`W_i` and :math:`W_j` transform node :math:`i`'s and node :math:`j`'s
features into the same dimension, so that when compute note features' similarity,
we can use dot-product.
"""
it can use dot-product.
Parameters
----------
in_feats : int, or pair of ints
Input feature size; i.e, the number of dimensions of :math:`h_i^{(l)}`.
DotGatConv can be applied on homogeneous graph and unidirectional
`bipartite graph <https://docs.dgl.ai/generated/dgl.bipartite.html?highlight=bipartite>`__.
If the layer is to be applied to a unidirectional bipartite graph, ``in_feats``
specifies the input feature size on both the source and destination nodes. If
a scalar is given, the source and destination node feature size would take the
same value.
out_feats : int
Output feature size; i.e, the number of dimensions of :math:`h_i^{(l+1)}`.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import DotGatConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> gatconv = DotGatConv(10, 2)
>>> res = gatconv(g, feat)
>>> res
tensor([[-0.6958, -0.8752],
[-0.6958, -0.8752],
[-0.6958, -0.8752],
[-0.6958, -0.8752],
[-0.6958, -0.8752],
[-0.6958, -0.8752]], grad_fn=<CopyReduceBackward>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_feat = th.tensor(np.random.rand(2, 5).astype(np.float32))
>>> v_feat = th.tensor(np.random.rand(4, 10).astype(np.float32))
>>> gatconv = DotGatConv((5,10), 2)
>>> res = gatconv(g, (u_feat, v_feat))
>>> res
tensor([[ 0.4718, 0.0864],
[ 0.7099, -0.0335],
[ 0.5869, 0.0284],
[ 0.4718, 0.0864]], grad_fn=<CopyReduceBackward>)
"""
def __init__(self,
in_feats,
out_feats
):
out_feats,
allow_zero_in_degree=False):
super(DotGatConv, self).__init__()
self._in_src_feats, self._in_dst_feats = expand_as_pair(in_feats)
self._out_feats = out_feats
self._allow_zero_in_degree = allow_zero_in_degree
if isinstance(in_feats, tuple):
self.fc_src = nn.Linear(self._in_src_feats, self._out_feats, bias=False)
......@@ -40,7 +115,11 @@ class DotGatConv(nn.Module):
self.fc = nn.Linear(self._in_src_feats, self._out_feats, bias=False)
def forward(self, graph, feat):
r"""Apply dot product version of self attention in GCN.
r"""
Description
-----------
Apply dot product version of self attention in GCN.
Parameters
----------
......@@ -57,10 +136,29 @@ class DotGatConv(nn.Module):
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}` is size
of output feature.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
graph = graph.local_var()
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
# check if feat is a tuple
if isinstance(feat, tuple):
h_src = feat[0]
......
......@@ -2,37 +2,102 @@
# pylint: disable= no-member, arguments-differ, invalid-name
from torch import nn
from ....base import DGLError
from .... import function as fn
from ....utils import expand_as_pair
class EdgeConv(nn.Module):
r"""EdgeConv layer.
r"""
Description
-----------
EdgeConv layer.
Introduced in "`Dynamic Graph CNN for Learning on Point Clouds
<https://arxiv.org/pdf/1801.07829>`__". Can be described as follows:
.. math::
x_i^{(l+1)} = \max_{j \in \mathcal{N}(i)} \mathrm{ReLU}(
\Theta \cdot (x_j^{(l)} - x_i^{(l)}) + \Phi \cdot x_i^{(l)})
h_i^{(l+1)} = \max_{j \in \mathcal{N}(i)} \mathrm{ReLU}(
\Theta \cdot (h_j^{(l)} - h_i^{(l)}) + \Phi \cdot h_i^{(l)})
where :math:`\mathcal{N}(i)` is the neighbor of :math:`i`.
:math:`\Theta` and :math:`\Phi` are linear layers.
Parameters
----------
in_feat : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
out_feat : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
batch_norm : bool
Whether to include batch normalization on messages.
Whether to include batch normalization on messages. Default: ``False``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import EdgeConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> conv = EdgeConv(10, 2)
>>> res = conv(g, feat)
>>> res
tensor([[-0.2347, 0.5849],
[-0.2347, 0.5849],
[-0.2347, 0.5849],
[-0.2347, 0.5849],
[-0.2347, 0.5849],
[-0.2347, 0.5849]], grad_fn=<CopyReduceBackward>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_fea = th.rand(2, 5)
>>> v_fea = th.rand(4, 5)
>>> conv = EdgeConv(5, 2, 3)
>>> res = conv(g, (u_fea, v_fea))
>>> res
tensor([[ 1.6375, 0.2085],
[-1.1925, -1.2852],
[ 0.2101, 1.3466],
[ 0.2342, -0.9868]], grad_fn=<CopyReduceBackward>)
"""
def __init__(self,
in_feat,
out_feat,
batch_norm=False):
batch_norm=False,
allow_zero_in_degree=False):
super(EdgeConv, self).__init__()
self.batch_norm = batch_norm
self._allow_zero_in_degree = allow_zero_in_degree
self.theta = nn.Linear(in_feat, out_feat)
self.phi = nn.Linear(in_feat, out_feat)
......@@ -47,27 +112,51 @@ class EdgeConv(nn.Module):
phi_x = self.phi(edges.src['x'])
return {'e': theta_x + phi_x}
def forward(self, g, h):
"""Forward computation
def forward(self, g, feat):
"""
Description
-----------
Forward computation
Parameters
----------
g : DGLGraph
The graph.
h : Tensor or pair of tensors
feat : Tensor or pair of tensors
:math:`(N, D)` where :math:`N` is the number of nodes and
:math:`D` is the number of feature dimensions.
If a pair of tensors is given, the graph must be a uni-bipartite graph
with only one edge type, and the two tensors must have the same
dimensionality on all except the first axis.
Returns
-------
torch.Tensor
New node features.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
with g.local_scope():
h_src, h_dst = expand_as_pair(h, g)
if not self._allow_zero_in_degree:
if (g.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
h_src, h_dst = expand_as_pair(feat, g)
g.srcdata['x'] = h_src
g.dstdata['x'] = h_dst
if not self.batch_norm:
......
......@@ -5,12 +5,17 @@ from torch import nn
from .... import function as fn
from ....ops import edge_softmax
from ....base import DGLError
from ..utils import Identity
from ....utils import expand_as_pair
# pylint: enable=W0235
class GATConv(nn.Module):
r"""Apply `Graph Attention Network <https://arxiv.org/pdf/1710.10903.pdf>`__
r"""
Description
-----------
Apply `Graph Attention Network <https://arxiv.org/pdf/1710.10903.pdf>`__
over an input signal.
.. math::
......@@ -20,29 +25,112 @@ class GATConv(nn.Module):
node :math:`j`:
.. math::
\alpha_{ij}^{l} & = \mathrm{softmax_i} (e_{ij}^{l})
\alpha_{ij}^{l} &= \mathrm{softmax_i} (e_{ij}^{l})
e_{ij}^{l} & = \mathrm{LeakyReLU}\left(\vec{a}^T [W h_{i} \| W h_{j}]\right)
e_{ij}^{l} &= \mathrm{LeakyReLU}\left(\vec{a}^T [W h_{i} \| W h_{j}]\right)
Parameters
----------
in_feats : int
Input feature size.
in_feats : int, or pair of ints
Input feature size; i.e, the number of dimensions of :math:`h_i^{(l)}`.
ATConv can be applied on homogeneous graph and unidirectional
`bipartite graph <https://docs.dgl.ai/generated/dgl.bipartite.html?highlight=bipartite>`__.
If the layer is to be applied to a unidirectional bipartite graph, ``in_feats``
specifies the input feature size on both the source and destination nodes. If
a scalar is given, the source and destination node feature size would take the
same value.
out_feats : int
Output feature size.
Output feature size; i.e, the number of dimensions of :math:`h_i^{(l+1)}`.
num_heads : int
Number of heads in Multi-Head Attention.
feat_drop : float, optional
Dropout rate on feature, defaults: ``0``.
Dropout rate on feature. Defaults: ``0``.
attn_drop : float, optional
Dropout rate on attention weight, defaults: ``0``.
Dropout rate on attention weight. Defaults: ``0``.
negative_slope : float, optional
LeakyReLU angle of negative slope.
LeakyReLU angle of negative slope. Defaults: ``0.2``.
residual : bool, optional
If True, use residual connection.
If True, use residual connection. Defaults: ``False``.
activation : callable activation function/layer or None, optional.
If not None, applies an activation function to the updated node features.
Default: ``None``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Defaults: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import GATConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> gatconv = GATConv(10, 2, num_heads=3)
>>> res = gatconv(g, feat)
>>> res
tensor([[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]],
[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]],
[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]],
[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]],
[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]],
[[ 3.4570, 1.8634],
[ 1.3805, -0.0762],
[ 1.0390, -1.1479]]], grad_fn=<BinaryReduceBackward>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_feat = th.tensor(np.random.rand(2, 5).astype(np.float32))
>>> v_feat = th.tensor(np.random.rand(4, 10).astype(np.float32))
>>> gatconv = GATConv((5,10), 2, 3)
>>> res = gatconv(g, (u_feat, v_feat))
>>> res
tensor([[[-0.6066, 1.0268],
[-0.5945, -0.4801],
[ 0.1594, 0.3825]],
[[ 0.0268, 1.0783],
[ 0.5041, -1.3025],
[ 0.6568, 0.7048]],
[[-0.2688, 1.0543],
[-0.0315, -0.9016],
[ 0.3943, 0.5347]],
[[-0.6066, 1.0268],
[-0.5945, -0.4801],
[ 0.1594, 0.3825]]], grad_fn=<BinaryReduceBackward>)
"""
def __init__(self,
in_feats,
......@@ -52,11 +140,19 @@ class GATConv(nn.Module):
attn_drop=0.,
negative_slope=0.2,
residual=False,
activation=None):
activation=None,
allow_zero_in_degree=False):
super(GATConv, self).__init__()
self._num_heads = num_heads
self._in_src_feats, self._in_dst_feats = expand_as_pair(in_feats)
self._out_feats = out_feats
self._allow_zero_in_degree = allow_zero_in_degree
if isinstance(in_feats, tuple):
self.fc_src = nn.Linear(
self._in_src_feats, out_feats * num_heads, bias=False)
self.fc_dst = nn.Linear(
self._in_dst_feats, out_feats * num_heads, bias=False)
else:
self.fc = nn.Linear(
self._in_src_feats, out_feats * num_heads, bias=False)
self.attn_l = nn.Parameter(th.FloatTensor(size=(1, num_heads, out_feats)))
......@@ -76,7 +172,17 @@ class GATConv(nn.Module):
self.activation = activation
def reset_parameters(self):
"""Reinitialize learnable parameters."""
"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The fc weights :math:`W^{(l)}` are initialized using Glorot uniform initialization.
The attention weights are using xavier initialization method.
"""
gain = nn.init.calculate_gain('relu')
nn.init.xavier_normal_(self.fc.weight, gain=gain)
nn.init.xavier_normal_(self.attn_l, gain=gain)
......@@ -85,7 +191,11 @@ class GATConv(nn.Module):
nn.init.xavier_normal_(self.res_fc.weight, gain=gain)
def forward(self, graph, feat):
r"""Compute graph attention network layer.
r"""
Description
-----------
Compute graph attention network layer.
Parameters
----------
......@@ -102,8 +212,27 @@ class GATConv(nn.Module):
torch.Tensor
The output feature of shape :math:`(N, H, D_{out})` where :math:`H`
is the number of heads, and :math:`D_{out}` is size of output feature.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
if isinstance(feat, tuple):
h_src = self.feat_drop(feat[0])
h_dst = self.feat_drop(feat[1])
......
......@@ -8,28 +8,58 @@ from .... import function as fn
class GatedGraphConv(nn.Module):
r"""Gated Graph Convolution layer from paper `Gated Graph Sequence
r"""
Description
-----------
Gated Graph Convolution layer from paper `Gated Graph Sequence
Neural Networks <https://arxiv.org/pdf/1511.05493.pdf>`__.
.. math::
h_{i}^{0} & = [ x_i \| \mathbf{0} ]
h_{i}^{0} &= [ x_i \| \mathbf{0} ]
a_{i}^{t} & = \sum_{j\in\mathcal{N}(i)} W_{e_{ij}} h_{j}^{t}
a_{i}^{t} &= \sum_{j\in\mathcal{N}(i)} W_{e_{ij}} h_{j}^{t}
h_{i}^{t+1} & = \mathrm{GRU}(a_{i}^{t}, h_{i}^{t})
h_{i}^{t+1} &= \mathrm{GRU}(a_{i}^{t}, h_{i}^{t})
Parameters
----------
in_feats : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`x_i`.
out_feats : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(t+1)}`.
n_steps : int
Number of recurrent steps.
Number of recurrent steps; i.e, the :math:`t` in the above formula.
n_etypes : int
Number of edge types.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import GatedGraphConv
>>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> feat = th.ones(6, 10)
>>> conv = GatedGraphConv(10, 10, 2, 3)
>>> etype = th.tensor([0,1,2,0,1,2])
>>> res = conv(g, feat, etype)
>>> res
tensor([[ 0.4652, 0.4458, 0.5169, 0.4126, 0.4847, 0.2303, 0.2757, 0.7721,
0.0523, 0.0857],
[ 0.0832, 0.1388, -0.5643, 0.7053, -0.2524, -0.3847, 0.7587, 0.8245,
0.9315, 0.4063],
[ 0.6340, 0.4096, 0.7692, 0.2125, 0.2106, 0.4542, -0.0580, 0.3364,
-0.1376, 0.4948],
[ 0.5551, 0.7946, 0.6220, 0.8058, 0.5711, 0.3063, -0.5454, 0.2272,
-0.6931, -0.1607],
[ 0.2644, 0.2469, -0.6143, 0.6008, -0.1516, -0.3781, 0.5878, 0.7993,
0.9241, 0.1835],
[ 0.6393, 0.3447, 0.3893, 0.4279, 0.3342, 0.3809, 0.0406, 0.5030,
0.1342, 0.0425]], grad_fn=<AddBackward0>)
"""
def __init__(self,
in_feats,
......@@ -49,7 +79,17 @@ class GatedGraphConv(nn.Module):
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
r"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The model parameters are initialized using Glorot uniform initialization
and the bias is initialized to be zero.
"""
gain = init.calculate_gain('relu')
self.gru.reset_parameters()
for linear in self.linears:
......@@ -57,7 +97,11 @@ class GatedGraphConv(nn.Module):
init.zeros_(linear.bias)
def forward(self, graph, feat, etypes):
"""Compute Gated Graph Convolution layer.
"""
Description
-----------
Compute Gated Graph Convolution layer.
Parameters
----------
......
......@@ -4,11 +4,16 @@ import torch as th
from torch import nn
from .... import function as fn
from ....base import DGLError
from ....utils import expand_as_pair
class GINConv(nn.Module):
r"""Graph Isomorphism Network layer from paper `How Powerful are Graph
r"""
Description
-----------
Graph Isomorphism Network layer from paper `How Powerful are Graph
Neural Networks? <https://arxiv.org/pdf/1810.00826.pdf>`__.
.. math::
......@@ -26,15 +31,66 @@ class GINConv(nn.Module):
init_eps : float, optional
Initial :math:`\epsilon` value, default: ``0``.
learn_eps : bool, optional
If True, :math:`\epsilon` will be a learnable parameter.
If True, :math:`\epsilon` will be a learnable parameter. Default: ``False``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Example
-------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import GINConv
>>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> lin = th.nn.Linear(10, 10)
>>> conv = GINConv(lin, 'max')
>>> res = conv(g, feat)
>>> res
tensor([[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468],
[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468],
[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468],
[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468],
[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468],
[ 1.2330, -0.1572, 0.0622, -3.1567, -2.2414, -0.7275, 0.6311, 1.0396,
1.7008, -1.2468]], grad_fn=<AddmmBackward>)
"""
def __init__(self,
apply_func,
aggregator_type,
init_eps=0,
learn_eps=False):
learn_eps=False,
allow_zero_in_degree=False):
super(GINConv, self).__init__()
self.apply_func = apply_func
self._aggregator_type = aggregator_type
if aggregator_type == 'sum':
self._reducer = fn.sum
elif aggregator_type == 'max':
......@@ -48,9 +104,14 @@ class GINConv(nn.Module):
self.eps = th.nn.Parameter(th.FloatTensor([init_eps]))
else:
self.register_buffer('eps', th.FloatTensor([init_eps]))
self._allow_zero_in_degree = allow_zero_in_degree
def forward(self, graph, feat):
r"""Compute Graph Isomorphism Network layer.
r"""
Description
-----------
Compute Graph Isomorphism Network layer.
Parameters
----------
......@@ -71,8 +132,28 @@ class GINConv(nn.Module):
:math:`D_{out}` is the output dimensionality of ``apply_func``.
If ``apply_func`` is None, :math:`D_{out}` should be the same
as input dimensionality.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any() and \
(self._aggregator_type not in ['sum', 'mean']):
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
feat_src, feat_dst = expand_as_pair(feat, graph)
graph.srcdata['h'] = feat_src
graph.update_all(fn.copy_u('h', 'm'), self._reducer('m', 'neigh'))
......
......@@ -5,37 +5,107 @@ from torch import nn
from torch.nn import init
from .... import function as fn
from ....base import DGLError
from ..utils import Identity
from ....utils import expand_as_pair
class GMMConv(nn.Module):
r"""The Gaussian Mixture Model Convolution layer from `Geometric Deep
r"""
Description
-----------
The Gaussian Mixture Model Convolution layer from `Geometric Deep
Learning on Graphs and Manifolds using Mixture Model CNNs
<http://openaccess.thecvf.com/content_cvpr_2017/papers/Monti_Geometric_Deep_Learning_CVPR_2017_paper.pdf>`__.
.. math::
h_i^{l+1} & = \mathrm{aggregate}\left(\left\{\frac{1}{K}
u_{ij} &= f(x_i, x_j), x_j \in \mathcal{N}(i)
w_k(u) &= \exp\left(-\frac{1}{2}(u-\mu_k)^T \Sigma_k^{-1} (u - \mu_k)\right)
h_i^{l+1} &= \mathrm{aggregate}\left(\left\{\frac{1}{K}
\sum_{k}^{K} w_k(u_{ij}), \forall j\in \mathcal{N}(i)\right\}\right)
w_k(u) & = \exp\left(-\frac{1}{2}(u-\mu_k)^T \Sigma_k^{-1} (u - \mu_k)\right)
where :math:`u` denotes the pseudo-coordinates between a vertex and one of its neighbor,
computed using function :math:`f`, :math:`\Sigma_k^{-1}` and :math:`\mu_k` are
learnable parameters representing the covariance matrix and mean vector of a Gaussian kernel.
Parameters
----------
in_feats : int
Number of input features.
Number of input features; i.e., the number of dimensions of :math:`x_i`.
out_feats : int
Number of output features.
Number of output features; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
dim : int
Dimensionality of pseudo-coordinte.
Dimensionality of pseudo-coordinte; i.e, the number of dimensions of :math:`u_{ij}`.
n_kernels : int
Number of kernels :math:`K`.
aggregator_type : str
Aggregator type (``sum``, ``mean``, ``max``).
Aggregator type (``sum``, ``mean``, ``max``). Default: ``sum``.
residual : bool
If True, use residual connection inside this layer. Default: ``False``.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import GMMConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> conv = GMMConv(10, 2, 3, 2, 'mean')
>>> pseudo = th.ones(12, 3)
>>> res = conv(g, feat, pseudo)
>>> res
tensor([[-0.3462, -0.2654],
[-0.3462, -0.2654],
[-0.3462, -0.2654],
[-0.3462, -0.2654],
[-0.3462, -0.2654],
[-0.3462, -0.2654]], grad_fn=<AddBackward0>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_fea = th.rand(2, 5)
>>> v_fea = th.rand(4, 10)
>>> pseudo = th.ones(5, 3)
>>> conv = GMMConv((10, 5), 2, 3, 2, 'mean')
>>> res = conv(g, (u_fea, v_fea), pseudo)
>>> res
tensor([[-0.1107, -0.1559],
[-0.1646, -0.2326],
[-0.1377, -0.1943],
[-0.1107, -0.1559]], grad_fn=<AddBackward0>)
"""
def __init__(self,
in_feats,
......@@ -44,12 +114,14 @@ class GMMConv(nn.Module):
n_kernels,
aggregator_type='sum',
residual=False,
bias=True):
bias=True,
allow_zero_in_degree=False):
super(GMMConv, self).__init__()
self._in_src_feats, self._in_dst_feats = expand_as_pair(in_feats)
self._out_feats = out_feats
self._dim = dim
self._n_kernels = n_kernels
self._allow_zero_in_degree = allow_zero_in_degree
if aggregator_type == 'sum':
self._reducer = fn.sum
elif aggregator_type == 'mean':
......@@ -77,7 +149,19 @@ class GMMConv(nn.Module):
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
r"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The fc parameters are initialized using Glorot uniform initialization
and the bias is initialized to be zero.
The mu weight is initialized using normal distribution and
inv_sigma is initialized with constant value 1.0.
"""
gain = init.calculate_gain('relu')
init.xavier_normal_(self.fc.weight, gain=gain)
if isinstance(self.res_fc, nn.Linear):
......@@ -88,7 +172,11 @@ class GMMConv(nn.Module):
init.zeros_(self.bias.data)
def forward(self, graph, feat, pseudo):
"""Compute Gaussian Mixture Model Convolution layer.
"""
Description
-----------
Compute Gaussian Mixture Model Convolution layer.
Parameters
----------
......@@ -109,8 +197,27 @@ class GMMConv(nn.Module):
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is the output feature size.
Raises
------
DGLError
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
feat_src, feat_dst = expand_as_pair(feat, graph)
graph.srcdata['h'] = self.fc(feat_src).view(-1, self._n_kernels, self._out_feats)
E = graph.number_of_edges()
......
......@@ -10,40 +10,27 @@ from ....utils import expand_as_pair
# pylint: disable=W0235
class GraphConv(nn.Module):
r"""Apply graph convolution over an input signal.
r"""
Graph convolution is introduced in `GCN <https://arxiv.org/abs/1609.02907>`__
and can be described as below:
Description
-----------
Graph convolution was introduced in `GCN <https://arxiv.org/abs/1609.02907>`__
and mathematically is defined as follows:
.. math::
h_i^{(l+1)} = \sigma(b^{(l)} + \sum_{j\in\mathcal{N}(i)}\frac{1}{c_{ij}}h_j^{(l)}W^{(l)})
where :math:`\mathcal{N}(i)` is the neighbor set of node :math:`i`. :math:`c_{ij}` is equal
to the product of the square root of node degrees:
:math:`\sqrt{|\mathcal{N}(i)|}\sqrt{|\mathcal{N}(j)|}`. :math:`\sigma` is an activation
function.
The model parameters are initialized as in the
`original implementation <https://github.com/tkipf/gcn/blob/master/gcn/layers.py>`__ where
the weight :math:`W^{(l)}` is initialized using Glorot uniform initialization
and the bias is initialized to be zero.
Notes
-----
Zero in degree nodes could lead to invalid normalizer. A common practice
to avoid this is to add a self-loop for each node in the graph, which
can be achieved by:
>>> g = ... # some DGLGraph
>>> g.add_edges(g.nodes(), g.nodes())
where :math:`\mathcal{N}(i)` is the set of neighbors of node :math:`i`,
:math:`c_{ij}` is the product of the square root of node degrees
(i.e., :math:`c_{ij} = \sqrt{|\mathcal{N}(i)|}\sqrt{|\mathcal{N}(j)|}`),
and :math:`\sigma` is an activation function.
Parameters
----------
in_feats : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
out_feats : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
norm : str, optional
How to apply the normalizer. If is `'right'`, divide the aggregated messages
by each node's in-degrees, which is equivalent to averaging the received messages.
......@@ -54,9 +41,15 @@ class GraphConv(nn.Module):
without a weight matrix.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
activation: callable activation function/layer or None, optional
activation : callable activation function/layer or None, optional
If not None, applies an activation function to the updated node features.
Default: ``None``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves. Default: ``False``.
Attributes
----------
......@@ -64,6 +57,68 @@ class GraphConv(nn.Module):
The learnable weight tensor.
bias : torch.Tensor
The learnable bias tensor.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import GraphConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> conv = GraphConv(10, 2, norm='both', weight=True, bias=True)
>>> res = conv(g, feat)
>>> print(res)
tensor([[ 1.3326, -0.2797],
[ 1.4673, -0.3080],
[ 1.3326, -0.2797],
[ 1.6871, -0.3541],
[ 1.7711, -0.3717],
[ 1.0375, -0.2178]], grad_fn=<AddBackward0>)
>>> # allow_zero_in_degree example
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> conv = GraphConv(10, 2, norm='both', weight=True, bias=True, allow_zero_in_degree=True)
>>> res = conv(g, feat)
>>> print(res)
tensor([[-0.2473, -0.4631],
[-0.3497, -0.6549],
[-0.3497, -0.6549],
[-0.4221, -0.7905],
[-0.3497, -0.6549],
[ 0.0000, 0.0000]], grad_fn=<AddBackward0>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_fea = th.rand(2, 5)
>>> v_fea = th.rand(4, 5)
>>> conv = GraphConv(5, 2, norm='both', weight=True, bias=True)
>>> res = conv(g, (u_fea, v_fea))
>>> res
tensor([[-0.2994, 0.6106],
[-0.4482, 0.5540],
[-0.5287, 0.8235],
[-0.2994, 0.6106]], grad_fn=<AddBackward0>)
"""
def __init__(self,
in_feats,
......@@ -71,7 +126,8 @@ class GraphConv(nn.Module):
norm='both',
weight=True,
bias=True,
activation=None):
activation=None,
allow_zero_in_degree=False):
super(GraphConv, self).__init__()
if norm not in ('none', 'both', 'right'):
raise DGLError('Invalid norm value. Must be either "none", "both" or "right".'
......@@ -79,6 +135,7 @@ class GraphConv(nn.Module):
self._in_feats = in_feats
self._out_feats = out_feats
self._norm = norm
self._allow_zero_in_degree = allow_zero_in_degree
if weight:
self.weight = nn.Parameter(th.Tensor(in_feats, out_feats))
......@@ -95,22 +152,31 @@ class GraphConv(nn.Module):
self._activation = activation
def reset_parameters(self):
"""Reinitialize learnable parameters."""
r"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The model parameters are initialized as in the
`original implementation <https://github.com/tkipf/gcn/blob/master/gcn/layers.py>`__
where the weight :math:`W^{(l)}` is initialized using Glorot uniform initialization
and the bias is initialized to be zero.
"""
if self.weight is not None:
init.xavier_uniform_(self.weight)
if self.bias is not None:
init.zeros_(self.bias)
def forward(self, graph, feat, weight=None):
r"""Compute graph convolution.
r"""
Notes
-----
* Input shape: :math:`(N, *, \text{in_feats})` where * means any number of additional
dimensions, :math:`N` is the number of nodes.
* Output shape: :math:`(N, *, \text{out_feats})` where all but the last dimension are
the same shape as the input.
* Weight shape: :math:`(\text{in_feats}, \text{out_feats})`.
Description
-----------
Compute graph convolution.
Parameters
----------
......@@ -120,11 +186,9 @@ class GraphConv(nn.Module):
If a torch.Tensor is given, it represents the input feature of shape
:math:`(N, D_{in})`
where :math:`D_{in}` is size of input feature, :math:`N` is the number of nodes.
If a pair of torch.Tensor is given, the pair must contain two tensors of shape
:math:`(N_{in}, D_{in_{src}})` and :math:`(N_{out}, D_{in_{dst}})`.
Note that in the special case of graph convolutional networks, if a pair of
tensors is given, the latter element will not participate in computation.
If a pair of torch.Tensor is given, which is the case for bipartite graph, the pair
must contain two tensors of shape :math:`(N_{in}, D_{in_{src}})` and
:math:`(N_{out}, D_{in_{dst}})`.
weight : torch.Tensor, optional
Optional external weight tensor.
......@@ -132,11 +196,42 @@ class GraphConv(nn.Module):
-------
torch.Tensor
The output feature
Raises
------
DGLError
Case 1:
If there are 0-in-degree nodes in the input graph, it will raise DGLError
since no message will be passed to those nodes. This will cause invalid output.
The error can be ignored by setting ``allow_zero_in_degree`` parameter to ``True``.
Case 2:
External weight is provided while at the same time the module
has defined its own weight parameter.
Notes
-----
* Input shape: :math:`(N, *, \text{in_feats})` where * means any number of additional
dimensions, :math:`N` is the number of nodes.
* Output shape: :math:`(N, *, \text{out_feats})` where all but the last dimension are
the same shape as the input.
* Weight shape: :math:`(\text{in_feats}, \text{out_feats})`.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
# (BarclayII) For RGCN on heterogeneous graphs we need to support GCN on bipartite.
feat_src, feat_dst = expand_as_pair(feat, graph)
if self._norm == 'both':
degs = graph.out_degrees().float().clamp(min=1)
norm = th.pow(degs, -0.5)
......
......@@ -4,30 +4,39 @@ import torch as th
from torch import nn
from torch.nn import init
from ....base import DGLError
from .... import function as fn
from ..utils import Identity
from ....utils import expand_as_pair
class NNConv(nn.Module):
r"""Graph Convolution layer introduced in `Neural Message Passing
r"""
Description
-----------
Graph Convolution layer introduced in `Neural Message Passing
for Quantum Chemistry <https://arxiv.org/pdf/1704.01212.pdf>`__.
.. math::
h_{i}^{l+1} = h_{i}^{l} + \mathrm{aggregate}\left(\left\{
f_\Theta (e_{ij}) \cdot h_j^{l}, j\in \mathcal{N}(i) \right\}\right)
where :math:`e_{ij}` is the edge feature, :math:`f_\Theta` is a function
with learnable parameters.
Parameters
----------
in_feats : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
NN can be applied on homogeneous graph and unidirectional
`bipartite graph <https://docs.dgl.ai/generated/dgl.bipartite.html?highlight=bipartite>`__.
If the layer is to be applied on a unidirectional bipartite graph, ``in_feats``
specifies the input feature size on both the source and destination nodes. If
a scalar is given, the source and destination node feature size would take the
same value.
out_feats : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
edge_func : callable activation function/layer
Maps each edge feature to a vector of shape
``(in_feats * out_feats)`` as weight to compute
......@@ -39,18 +48,81 @@ class NNConv(nn.Module):
If True, use residual connection. Default: ``False``.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
allow_zero_in_degree : bool, optional
If there are 0-in-degree nodes in the graph, output for those nodes will be invalid
since no message will be passed to those nodes. This is harmful for some applications
causing silent performance regression. This module will raise a DGLError if it detects
0-in-degree nodes in input graph. By setting ``True``, it will suppress the check
and let the users handle it by themselves.
Notes
-----
Zero in-degree nodes will lead to invalid output value. This is because no message
will be passed to those nodes, the aggregation function will be appied on empty input.
A common practice to avoid this is to add a self-loop for each node in the graph if
it is homogeneous, which can be achieved by:
>>> g = ... # a DGLGraph
>>> g = dgl.add_self_loop(g)
Calling ``add_self_loop`` will not work for some graphs, for example, heterogeneous graph
since the edge type can not be decided for self_loop edges. Set ``allow_zero_in_degree``
to ``True`` for those cases to unblock the code and handle zere-in-degree nodes manually.
A common practise to handle this is to filter out the nodes with zere-in-degree when use
after conv.
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import NNConv
>>> # Case 1: Homogeneous graph
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> g = dgl.add_self_loop(g)
>>> feat = th.ones(6, 10)
>>> lin = th.nn.Linear(5, 20)
>>> def edge_func(efeat):
... return lin(efeat)
>>> efeat = th.ones(6+6, 5)
>>> conv = NNConv(10, 2, edge_func, 'mean')
>>> res = conv(g, feat, efeat)
>>> res
tensor([[-1.5243, -0.2719],
[-1.5243, -0.2719],
[-1.5243, -0.2719],
[-1.5243, -0.2719],
[-1.5243, -0.2719],
[-1.5243, -0.2719]], grad_fn=<AddBackward0>)
>>> # Case 2: Unidirectional bipartite graph
>>> u = [0, 1, 0, 0, 1]
>>> v = [0, 1, 2, 3, 2]
>>> g = dgl.bipartite((u, v))
>>> u_feat = th.tensor(np.random.rand(2, 10).astype(np.float32))
>>> v_feat = th.tensor(np.random.rand(4, 10).astype(np.float32))
>>> conv = NNConv(10, 2, edge_func, 'mean')
>>> efeat = th.ones(5, 5)
>>> res = conv(g, (u_feat, v_feat), efeat)
>>> res
tensor([[-0.6568, 0.5042],
[ 0.9089, -0.5352],
[ 0.1261, -0.0155],
[-0.6568, 0.5042]], grad_fn=<AddBackward0>)
"""
def __init__(self,
in_feats,
out_feats,
edge_func,
aggregator_type,
aggregator_type='mean',
residual=False,
bias=True):
bias=True,
allow_zero_in_degree=False):
super(NNConv, self).__init__()
self._in_src_feats, self._in_dst_feats = expand_as_pair(in_feats)
self._out_feats = out_feats
self.edge_nn = edge_func
self.edge_func = edge_func
if aggregator_type == 'sum':
self.reducer = fn.sum
elif aggregator_type == 'mean':
......@@ -71,10 +143,21 @@ class NNConv(nn.Module):
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self._allow_zero_in_degree = allow_zero_in_degree
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
r"""
Description
-----------
Reinitialize learnable parameters.
Notes
-----
The model parameters are initialized using Glorot uniform initialization
and the bias is initialized to be zero.
"""
gain = init.calculate_gain('relu')
if self.bias is not None:
nn.init.zeros_(self.bias)
......@@ -94,7 +177,7 @@ class NNConv(nn.Module):
input feature size.
efeat : torch.Tensor
The edge feature of shape :math:`(N, *)`, should fit the input
shape requirement of ``edge_nn``.
shape requirement of ``edge_func``.
Returns
-------
......@@ -103,12 +186,24 @@ class NNConv(nn.Module):
is the output feature size.
"""
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
raise DGLError('There are 0-in-degree nodes in the graph, '
'output for those nodes will be invalid. '
'This is harmful for some applications, '
'causing silent performance regression. '
'Adding self-loop on the input graph by '
'calling `g = dgl.add_self_loop(g)` will resolve '
'the issue. Setting ``allow_zero_in_degree`` '
'to be `True` when constructing this module will '
'suppress the check and let the code run.')
feat_src, feat_dst = expand_as_pair(feat, graph)
# (n, d_in, 1)
graph.srcdata['h'] = feat_src.unsqueeze(-1)
# (n, d_in, d_out)
graph.edata['w'] = self.edge_nn(efeat).view(-1, self._in_src_feats, self._out_feats)
graph.edata['w'] = self.edge_func(efeat).view(-1, self._in_src_feats, self._out_feats)
# (n, d_in, d_out)
graph.update_all(fn.u_mul_e('h', 'w', 'm'), self.reducer('m', 'neigh'))
rst = graph.dstdata['neigh'].sum(dim=1) # (n, d_out)
......
......@@ -8,7 +8,11 @@ from .. import utils
class RelGraphConv(nn.Module):
r"""Relational graph convolution layer.
r"""
Description
-----------
Relational graph convolution layer.
Relational graph convolution is introduced in "`Modeling Relational Data with Graph
Convolutional Networks <https://arxiv.org/abs/1703.06103>`__"
......@@ -30,37 +34,82 @@ class RelGraphConv(nn.Module):
W_r^{(l)} = \sum_{b=1}^B a_{rb}^{(l)}V_b^{(l)}
where :math:`B` is the number of bases.
where :math:`B` is the number of bases, :math:`V_b^{(l)}` are linearly combined
with coefficients :math:`a_{rb}^{(l)}`.
The block-diagonal-decomposition regularization decomposes :math:`W_r` into :math:`B`
number of block diagonal matrices. We refer :math:`B` as the number of bases.
The block regularization decomposes :math:`W_r` by:
.. math::
W_r^{(l)} = \oplus_{b=1}^B Q_{rb}^{(l)}
where :math:`B` is the number of bases, :math:`Q_{rb}^{(l)}` are block
bases with shape :math:`R^{(d^{(l+1)}/B)*(d^{l}/B)}`.
Parameters
----------
in_feat : int
Input feature size.
Input feature size; i.e, the number of dimensions of :math:`h_j^{(l)}`.
out_feat : int
Output feature size.
Output feature size; i.e., the number of dimensions of :math:`h_i^{(l+1)}`.
num_rels : int
Number of relations.
Number of relations. .
regularizer : str
Which weight regularizer to use "basis" or "bdd"
Which weight regularizer to use "basis" or "bdd".
"basis" is short for basis-diagonal-decomposition.
"bdd" is short for block-diagonal-decomposition.
num_bases : int, optional
Number of bases. If is none, use number of relations. Default: None.
Number of bases. If is none, use number of relations. Default: ``None``.
bias : bool, optional
True if bias is added. Default: True
True if bias is added. Default: ``True``.
activation : callable, optional
Activation function. Default: None
Activation function. Default: ``None``.
self_loop : bool, optional
True to include self loop message. Default: False
True to include self loop message. Default: ``True``.
low_mem : bool, optional
True to use low memory implementation of relation message passing function. Default: False
This option trade speed with memory consumption, and will slowdown the forward/backward.
Turn it on when you encounter OOM problem during training or evaluation.
True to use low memory implementation of relation message passing function. Default: False.
This option trades speed with memory consumption, and will slowdown the forward/backward.
Turn it on when you encounter OOM problem during training or evaluation. Default: ``False``.
dropout : float, optional
Dropout rate. Default: 0.0
Dropout rate. Default: ``0.0``
layer_norm: float, optional
Add layer norm. Default: False
Add layer norm. Default: ``False``
Examples
--------
>>> import dgl
>>> import numpy as np
>>> import torch as th
>>> from dgl.nn import RelGraphConv
>>>
>>> g = dgl.graph(([0,1,2,3,2,5], [1,2,3,4,0,3]))
>>> feat = th.ones(6, 10)
>>> conv = RelGraphConv(10, 2, 3, regularizer='basis', num_bases=2)
>>> conv.weight.shape
torch.Size([2, 10, 2])
>>> etype = th.tensor(np.array([0,1,2,0,1,2]).astype(np.int64))
>>> res = conv(g, feat, etype)
>>> res
tensor([[ 0.3996, -2.3303],
[-0.4323, -0.1440],
[ 0.3996, -2.3303],
[ 2.1046, -2.8654],
[-0.4323, -0.1440],
[-0.1309, -1.0000]], grad_fn=<AddBackward0>)
>>> # One-hot input
>>> one_hot_feat = th.tensor(np.array([0,1,2,3,4,5]).astype(np.int64))
>>> res = conv(g, one_hot_feat, etype)
>>> res
tensor([[ 0.5925, 0.0985],
[-0.3953, 0.8408],
[-0.9819, 0.5284],
[-1.0085, -0.1721],
[ 0.5962, 1.2002],
[ 0.0365, -0.3532]], grad_fn=<AddBackward0>)
"""
def __init__(self,
in_feat,
......@@ -70,7 +119,7 @@ class RelGraphConv(nn.Module):
num_bases=None,
bias=True,
activation=None,
self_loop=False,
self_loop=True,
low_mem=False,
dropout=0.0,
layer_norm=False):
......@@ -193,22 +242,28 @@ class RelGraphConv(nn.Module):
msg = msg * edges.data['norm']
return {'msg': msg}
def forward(self, g, x, etypes, norm=None):
""" Forward computation
def forward(self, g, feat, etypes, norm=None):
"""
Description
-----------
Forward computation
Parameters
----------
g : DGLGraph
The graph.
x : torch.Tensor
feat : torch.Tensor
Input node features. Could be either
* :math:`(|V|, D)` dense tensor
* :math:`(|V|,)` int64 vector, representing the categorical values of each
node. We then treat the input feature as an one-hot encoding feature.
node. It then treat the input feature as an one-hot encoding feature.
etypes : torch.Tensor
Edge type tensor. Shape: :math:`(|E|,)`
norm : torch.Tensor
Optional edge normalizer tensor. Shape: :math:`(|E|, 1)`
Optional edge normalizer tensor. Shape: :math:`(|E|, 1)`.
Returns
-------
......@@ -216,12 +271,12 @@ class RelGraphConv(nn.Module):
New node features.
"""
with g.local_scope():
g.srcdata['h'] = x
g.srcdata['h'] = feat
g.edata['type'] = etypes
if norm is not None:
g.edata['norm'] = norm
if self.self_loop:
loop_message = utils.matmul_maybe_select(x[:g.number_of_dst_nodes()],
loop_message = utils.matmul_maybe_select(feat[:g.number_of_dst_nodes()],
self.loop_weight)
# message passing
g.update_all(self.message_func, fn.sum(msg='msg', out='h'))
......
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