项目文件夹

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xiang song(charlie.song) e17add5602 [NN] Add MXNet impl for TAGCN module. (#799)
* upd

* fig edgebatch edges

* add test

* trigger

* Update README.md for pytorch PinSage example.

Add noting that the PinSage model example under
example/pytorch/recommendation only work with Python 3.6+
as its dataset loader depends on stanfordnlp package
which work only with Python 3.6+.

* Provid a frame agnostic API to test nn modules on both CPU and CUDA side.

1. make dgl.nn.xxx frame agnostic
2. make test.backend include dgl.nn modules
3. modify test_edge_softmax of test/mxnet/test_nn.py and
    test/pytorch/test_nn.py work on both CPU and GPU

* Fix style

* Delete unused code

* Make agnostic test only related to tests/backend

1. clear all agnostic related code in dgl.nn
2. make test_graph_conv agnostic to cpu/gpu

* Fix code style

* fix

* doc

* Make all test code under tests.mxnet/pytorch.test_nn.py
work on both CPU and GPU.

* Fix syntex

* Remove rand

* Add TAGCN nn.module and example

* Now tagcn can run on CPU.

* Add unitest for TGConv

* Fix style

* For pubmed dataset, using --lr=0.005 can achieve better acc

* Fix style

* Fix some descriptions

* trigger

* Fix doc

* Add nn.TGConv and example

* Fix bug

* Update data in mxnet.tagcn test acc.

* Fix some comments and code

* delete useless code

* Fix namming

* Fix bug

* Fix bug

* Add test code for mxnet TAGCov

* Update some docs

* Fix some code

* Update docs dgl.nn.mxnet

* Update weight init

* Fix
2019-08-28 13:19:17 +08:00

1770 行
61 KiB
Python

"""Torch modules for graph convolutions."""
# pylint: disable= no-member, arguments-differ, invalid-name
import torch as th
from torch import nn
from torch.nn import init
import torch.nn.functional as F
from . import utils
from ... import function as fn
from ...batched_graph import broadcast_nodes
from ...transform import laplacian_lambda_max
from .softmax import edge_softmax
__all__ = ['GraphConv', 'GATConv', 'TAGConv', 'RelGraphConv', 'SAGEConv',
'SGConv', 'APPNPConv', 'GINConv', 'GatedGraphConv', 'GMMConv',
'ChebConv', 'AGNNConv', 'NNConv', 'DenseGraphConv', 'DenseSAGEConv',
'DenseChebConv', 'EdgeConv']
# pylint: disable=W0235
class Identity(nn.Module):
"""A placeholder identity operator that is argument-insensitive.
(Identity has already been supported by PyTorch 1.2, we will directly
import torch.nn.Identity in the future)
"""
def __init__(self):
super(Identity, self).__init__()
def forward(self, x):
"""Return input"""
return x
# pylint: enable=W0235
class GraphConv(nn.Module):
r"""Apply graph convolution over an input signal.
Graph convolution is introduced in `GCN <https://arxiv.org/abs/1609.02907>`__
and can be described as below:
.. 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())
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
norm : bool, optional
If True, the normalizer :math:`c_{ij}` is applied. Default: ``True``.
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``.
Attributes
----------
weight : torch.Tensor
The learnable weight tensor.
bias : torch.Tensor
The learnable bias tensor.
"""
def __init__(self,
in_feats,
out_feats,
norm=True,
bias=True,
activation=None):
super(GraphConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._norm = norm
self.weight = nn.Parameter(th.Tensor(in_feats, out_feats))
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_parameter('bias', None)
self.reset_parameters()
self._activation = activation
def reset_parameters(self):
"""Reinitialize learnable parameters."""
init.xavier_uniform_(self.weight)
if self.bias is not None:
init.zeros_(self.bias)
def forward(self, graph, feat):
r"""Compute graph convolution.
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.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature
Returns
-------
torch.Tensor
The output feature
"""
graph = graph.local_var()
if self._norm:
norm = th.pow(graph.in_degrees().float().clamp(min=1), -0.5)
shp = norm.shape + (1,) * (feat.dim() - 1)
norm = th.reshape(norm, shp).to(feat.device)
feat = feat * norm
if self._in_feats > self._out_feats:
# mult W first to reduce the feature size for aggregation.
feat = th.matmul(feat, self.weight)
graph.ndata['h'] = feat
graph.update_all(fn.copy_src(src='h', out='m'),
fn.sum(msg='m', out='h'))
rst = graph.ndata['h']
else:
# aggregate first then mult W
graph.ndata['h'] = feat
graph.update_all(fn.copy_src(src='h', out='m'),
fn.sum(msg='m', out='h'))
rst = graph.ndata['h']
rst = th.matmul(rst, self.weight)
if self._norm:
rst = rst * norm
if self.bias is not None:
rst = rst + self.bias
if self._activation is not None:
rst = self._activation(rst)
return rst
def extra_repr(self):
"""Set the extra representation of the module,
which will come into effect when printing the model.
"""
summary = 'in={_in_feats}, out={_out_feats}'
summary += ', normalization={_norm}'
if '_activation' in self.__dict__:
summary += ', activation={_activation}'
return summary.format(**self.__dict__)
class GATConv(nn.Module):
r"""Apply `Graph Attention Network <https://arxiv.org/pdf/1710.10903.pdf>`__
over an input signal.
.. math::
h_i^{(l+1)} = \sum_{j\in \mathcal{N}(i)} \alpha_{i,j} W^{(l)} h_j^{(l)}
where :math:`\alpha_{ij}` is the attention score bewteen node :math:`i` and
node :math:`j`:
.. math::
\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)
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
num_heads : int
Number of heads in Multi-Head Attention.
feat_drop : float, optional
Dropout rate on feature, defaults: ``0``.
attn_drop : float, optional
Dropout rate on attention weight, defaults: ``0``.
negative_slope : float, optional
LeakyReLU angle of negative slope.
residual : bool, optional
If True, use residual connection.
activation : callable activation function/layer or None, optional.
If not None, applies an activation function to the updated node features.
Default: ``None``.
"""
def __init__(self,
in_feats,
out_feats,
num_heads,
feat_drop=0.,
attn_drop=0.,
negative_slope=0.2,
residual=False,
activation=None):
super(GATConv, self).__init__()
self._num_heads = num_heads
self._in_feats = in_feats
self._out_feats = out_feats
self.fc = nn.Linear(in_feats, out_feats * num_heads, bias=False)
self.attn_l = nn.Parameter(th.FloatTensor(size=(1, num_heads, out_feats)))
self.attn_r = nn.Parameter(th.FloatTensor(size=(1, num_heads, out_feats)))
self.feat_drop = nn.Dropout(feat_drop)
self.attn_drop = nn.Dropout(attn_drop)
self.leaky_relu = nn.LeakyReLU(negative_slope)
if residual:
if in_feats != out_feats:
self.res_fc = nn.Linear(in_feats, num_heads * out_feats, bias=False)
else:
self.res_fc = Identity()
else:
self.register_buffer('res_fc', None)
self.reset_parameters()
self.activation = activation
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = nn.init.calculate_gain('relu')
nn.init.xavier_normal_(self.fc.weight, gain=gain)
nn.init.xavier_normal_(self.attn_l, gain=gain)
nn.init.xavier_normal_(self.attn_r, gain=gain)
if isinstance(self.res_fc, nn.Linear):
nn.init.xavier_normal_(self.res_fc.weight, gain=gain)
def forward(self, graph, feat):
r"""Compute graph attention network layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
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.
Returns
-------
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.
"""
graph = graph.local_var()
h = self.feat_drop(feat)
feat = self.fc(h).view(-1, self._num_heads, self._out_feats)
el = (feat * self.attn_l).sum(dim=-1).unsqueeze(-1)
er = (feat * self.attn_r).sum(dim=-1).unsqueeze(-1)
graph.ndata.update({'ft': feat, 'el': el, 'er': er})
# compute edge attention
graph.apply_edges(fn.u_add_v('el', 'er', 'e'))
e = self.leaky_relu(graph.edata.pop('e'))
# compute softmax
graph.edata['a'] = self.attn_drop(edge_softmax(graph, e))
# message passing
graph.update_all(fn.u_mul_e('ft', 'a', 'm'),
fn.sum('m', 'ft'))
rst = graph.ndata['ft']
# residual
if self.res_fc is not None:
resval = self.res_fc(h).view(h.shape[0], -1, self._out_feats)
rst = rst + resval
# activation
if self.activation:
rst = self.activation(rst)
return rst
class TAGConv(nn.Module):
r"""Topology Adaptive Graph Convolutional layer from paper `Topology
Adaptive Graph Convolutional Networks <https://arxiv.org/pdf/1710.10370.pdf>`__.
.. math::
\mathbf{X}^{\prime} = \sum_{k=0}^K \mathbf{D}^{-1/2} \mathbf{A}
\mathbf{D}^{-1/2}\mathbf{X} \mathbf{\Theta}_{k},
where :math:`\mathbf{A}` denotes the adjacency matrix and
:math:`D_{ii} = \sum_{j=0} A_{ij}` its diagonal degree matrix.
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
k: int, optional
Number of hops :math: `k`. (default: 2)
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``.
Attributes
----------
lin : torch.Module
The learnable linear module.
"""
def __init__(self,
in_feats,
out_feats,
k=2,
bias=True,
activation=None):
super(TAGConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._k = k
self._activation = activation
self.lin = nn.Linear(in_feats * (self._k + 1), out_feats, bias=bias)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = nn.init.calculate_gain('relu')
nn.init.xavier_normal_(self.lin.weight, gain=gain)
def forward(self, graph, feat):
r"""Compute topology adaptive graph convolution.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
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.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
graph = graph.local_var()
norm = th.pow(graph.in_degrees().float().clamp(min=1), -0.5)
shp = norm.shape + (1,) * (feat.dim() - 1)
norm = th.reshape(norm, shp).to(feat.device)
#D-1/2 A D -1/2 X
fstack = [feat]
for _ in range(self._k):
rst = fstack[-1] * norm
graph.ndata['h'] = rst
graph.update_all(fn.copy_src(src='h', out='m'),
fn.sum(msg='m', out='h'))
rst = graph.ndata['h']
rst = rst * norm
fstack.append(rst)
rst = self.lin(th.cat(fstack, dim=-1))
if self._activation is not None:
rst = self._activation(rst)
return rst
class RelGraphConv(nn.Module):
r"""Relational graph convolution layer.
Relational graph convolution is introduced in "`Modeling Relational Data with Graph
Convolutional Networks <https://arxiv.org/abs/1703.06103>`__"
and can be described as below:
.. math::
h_i^{(l+1)} = \sigma(\sum_{r\in\mathcal{R}}
\sum_{j\in\mathcal{N}^r(i)}\frac{1}{c_{i,r}}W_r^{(l)}h_j^{(l)}+W_0^{(l)}h_i^{(l)})
where :math:`\mathcal{N}^r(i)` is the neighbor set of node :math:`i` w.r.t. relation
:math:`r`. :math:`c_{i,r}` is the normalizer equal
to :math:`|\mathcal{N}^r(i)|`. :math:`\sigma` is an activation function. :math:`W_0`
is the self-loop weight.
The basis regularization decomposes :math:`W_r` by:
.. math::
W_r^{(l)} = \sum_{b=1}^B a_{rb}^{(l)}V_b^{(l)}
where :math:`B` is the number of bases.
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.
Parameters
----------
in_feat : int
Input feature size.
out_feat : int
Output feature size.
num_rels : int
Number of relations.
regularizer : str
Which weight regularizer to use "basis" or "bdd"
num_bases : int, optional
Number of bases. If is none, use number of relations. Default: None.
bias : bool, optional
True if bias is added. Default: True
activation : callable, optional
Activation function. Default: None
self_loop : bool, optional
True to include self loop message. Default: False
dropout : float, optional
Dropout rate. Default: 0.0
"""
def __init__(self,
in_feat,
out_feat,
num_rels,
regularizer="basis",
num_bases=None,
bias=True,
activation=None,
self_loop=False,
dropout=0.0):
super(RelGraphConv, self).__init__()
self.in_feat = in_feat
self.out_feat = out_feat
self.num_rels = num_rels
self.regularizer = regularizer
self.num_bases = num_bases
if self.num_bases is None or self.num_bases > self.num_rels or self.num_bases < 0:
self.num_bases = self.num_rels
self.bias = bias
self.activation = activation
self.self_loop = self_loop
if regularizer == "basis":
# add basis weights
self.weight = nn.Parameter(th.Tensor(self.num_bases, self.in_feat, self.out_feat))
if self.num_bases < self.num_rels:
# linear combination coefficients
self.w_comp = nn.Parameter(th.Tensor(self.num_rels, self.num_bases))
nn.init.xavier_uniform_(self.weight, gain=nn.init.calculate_gain('relu'))
if self.num_bases < self.num_rels:
nn.init.xavier_uniform_(self.w_comp,
gain=nn.init.calculate_gain('relu'))
# message func
self.message_func = self.basis_message_func
elif regularizer == "bdd":
if in_feat % num_bases != 0 or out_feat % num_bases != 0:
raise ValueError('Feature size must be a multiplier of num_bases.')
# add block diagonal weights
self.submat_in = in_feat // self.num_bases
self.submat_out = out_feat // self.num_bases
# assuming in_feat and out_feat are both divisible by num_bases
self.weight = nn.Parameter(th.Tensor(
self.num_rels, self.num_bases * self.submat_in * self.submat_out))
nn.init.xavier_uniform_(self.weight, gain=nn.init.calculate_gain('relu'))
# message func
self.message_func = self.bdd_message_func
else:
raise ValueError("Regularizer must be either 'basis' or 'bdd'")
# bias
if self.bias:
self.h_bias = nn.Parameter(th.Tensor(out_feat))
nn.init.zeros_(self.h_bias)
# weight for self loop
if self.self_loop:
self.loop_weight = nn.Parameter(th.Tensor(in_feat, out_feat))
nn.init.xavier_uniform_(self.loop_weight,
gain=nn.init.calculate_gain('relu'))
self.dropout = nn.Dropout(dropout)
def basis_message_func(self, edges):
"""Message function for basis regularizer"""
if self.num_bases < self.num_rels:
# generate all weights from bases
weight = self.weight.view(self.num_bases,
self.in_feat * self.out_feat)
weight = th.matmul(self.w_comp, weight).view(
self.num_rels, self.in_feat, self.out_feat)
else:
weight = self.weight
msg = utils.bmm_maybe_select(edges.src['h'], weight, edges.data['type'])
if 'norm' in edges.data:
msg = msg * edges.data['norm']
return {'msg': msg}
def bdd_message_func(self, edges):
"""Message function for block-diagonal-decomposition regularizer"""
if edges.src['h'].dtype == th.int64 and len(edges.src['h'].shape) == 1:
raise TypeError('Block decomposition does not allow integer ID feature.')
weight = self.weight.index_select(0, edges.data['type']).view(
-1, self.submat_in, self.submat_out)
node = edges.src['h'].view(-1, 1, self.submat_in)
msg = th.bmm(node, weight).view(-1, self.out_feat)
if 'norm' in edges.data:
msg = msg * edges.data['norm']
return {'msg': msg}
def forward(self, g, x, etypes, norm=None):
""" Forward computation
Parameters
----------
g : DGLGraph
The graph.
x : 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.
etypes : torch.Tensor
Edge type tensor. Shape: :math:`(|E|,)`
norm : torch.Tensor
Optional edge normalizer tensor. Shape: :math:`(|E|, 1)`
Returns
-------
torch.Tensor
New node features.
"""
g = g.local_var()
g.ndata['h'] = x
g.edata['type'] = etypes
if norm is not None:
g.edata['norm'] = norm
if self.self_loop:
loop_message = utils.matmul_maybe_select(x, self.loop_weight)
# message passing
g.update_all(self.message_func, fn.sum(msg='msg', out='h'))
# apply bias and activation
node_repr = g.ndata['h']
if self.bias:
node_repr = node_repr + self.h_bias
if self.self_loop:
node_repr = node_repr + loop_message
if self.activation:
node_repr = self.activation(node_repr)
node_repr = self.dropout(node_repr)
return node_repr
class EdgeConv(nn.Module):
r"""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)})
where :math:`\mathcal{N}(i)` is the neighbor of :math:`i`.
Parameters
----------
in_feat : int
Input feature size.
out_feat : int
Output feature size.
batch_norm : bool
Whether to include batch normalization on messages.
"""
def __init__(self, in_feat, out_feat, batch_norm=False):
super(EdgeConv, self).__init__()
self.batch_norm = batch_norm
self.theta = nn.Linear(in_feat, out_feat)
self.phi = nn.Linear(in_feat, out_feat)
if batch_norm:
self.bn = nn.BatchNorm1d(out_feat)
def message(self, edges):
"""The message computation function.
"""
theta_x = self.theta(edges.dst['x'] - edges.src['x'])
phi_x = self.phi(edges.src['x'])
return {'e': theta_x + phi_x}
def forward(self, g, h):
"""Forward computation
Parameters
----------
g : DGLGraph
The graph.
h : Tensor
:math:`(N, D)` where :math:`N` is the number of nodes and
:math:`D` is the number of feature dimensions.
Returns
-------
torch.Tensor
New node features.
"""
with g.local_scope():
g.ndata['x'] = h
if not self.batch_norm:
g.update_all(self.message, fn.max('e', 'x'))
else:
g.apply_edges(self.message)
# Although the official implementation includes a per-edge
# batch norm within EdgeConv, I choose to replace it with a
# global batch norm for a number of reasons:
#
# (1) When the point clouds within each batch do not have the
# same number of points, batch norm would not work.
#
# (2) Even if the point clouds always have the same number of
# points, the points may as well be shuffled even with the
# same (type of) object (and the official implementation
# *does* shuffle the points of the same example for each
# epoch).
#
# For example, the first point of a point cloud of an
# airplane does not always necessarily reside at its nose.
#
# In this case, the learned statistics of each position
# by batch norm is not as meaningful as those learned from
# images.
g.edata['e'] = self.bn(g.edata['e'])
g.update_all(fn.copy_e('e', 'e'), fn.max('e', 'x'))
return g.ndata['x']
class SAGEConv(nn.Module):
r"""GraphSAGE layer from paper `Inductive Representation Learning on
Large Graphs <https://arxiv.org/pdf/1706.02216.pdf>`__.
.. math::
h_{\mathcal{N}(i)}^{(l+1)} & = \mathrm{aggregate}
\left(\{h_{j}^{l}, \forall j \in \mathcal{N}(i) \}\right)
h_{i}^{(l+1)} & = \sigma \left(W \cdot \mathrm{concat}
(h_{i}^{l}, h_{\mathcal{N}(i)}^{l+1} + b) \right)
h_{i}^{(l+1)} & = \mathrm{norm}(h_{i}^{l})
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
feat_drop : float
Dropout rate on features, default: ``0``.
aggregator_type : str
Aggregator type to use (``mean``, ``gcn``, ``pool``, ``lstm``).
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
norm : callable activation function/layer or None, optional
If not None, applies normalization oto the updated node features.
activation : callable activation function/layer or None, optional
If not None, applies an activation function to the updated node features.
Default: ``None``.
"""
def __init__(self,
in_feats,
out_feats,
aggregator_type,
feat_drop=0.,
bias=True,
norm=None,
activation=None):
super(SAGEConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._aggre_type = aggregator_type
self.norm = norm
self.feat_drop = nn.Dropout(feat_drop)
self.activation = activation
# aggregator type: mean/pool/lstm/gcn
if aggregator_type == 'pool':
self.fc_pool = nn.Linear(in_feats, in_feats)
if aggregator_type == 'lstm':
self.lstm = nn.LSTM(in_feats, in_feats, batch_first=True)
if aggregator_type != 'gcn':
self.fc_self = nn.Linear(in_feats, out_feats, bias=bias)
self.fc_neigh = nn.Linear(in_feats, out_feats, bias=bias)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = nn.init.calculate_gain('relu')
if self._aggre_type == 'pool':
nn.init.xavier_uniform_(self.fc_pool.weight, gain=gain)
if self._aggre_type == 'lstm':
self.lstm.reset_parameters()
if self._aggre_type != 'gcn':
nn.init.xavier_uniform_(self.fc_self.weight, gain=gain)
nn.init.xavier_uniform_(self.fc_neigh.weight, gain=gain)
def _lstm_reducer(self, nodes):
"""LSTM reducer
NOTE(zihao): lstm reducer with default schedule (degree bucketing)
is slow, we could accelerate this with degree padding in the future.
"""
m = nodes.mailbox['m'] # (B, L, D)
batch_size = m.shape[0]
h = (m.new_zeros((1, batch_size, self._in_feats)),
m.new_zeros((1, batch_size, self._in_feats)))
_, (rst, _) = self.lstm(m, h)
return {'neigh': rst.squeeze(0)}
def forward(self, graph, feat):
r"""Compute GraphSAGE layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
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.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
graph = graph.local_var()
feat = self.feat_drop(feat)
h_self = feat
if self._aggre_type == 'mean':
graph.ndata['h'] = feat
graph.update_all(fn.copy_src('h', 'm'), fn.mean('m', 'neigh'))
h_neigh = graph.ndata['neigh']
elif self._aggre_type == 'gcn':
graph.ndata['h'] = feat
graph.update_all(fn.copy_src('h', 'm'), fn.sum('m', 'neigh'))
# divide in_degrees
degs = graph.in_degrees().float()
degs = degs.to(feat.device)
h_neigh = (graph.ndata['neigh'] + graph.ndata['h']) / (degs.unsqueeze(-1) + 1)
elif self._aggre_type == 'pool':
graph.ndata['h'] = F.relu(self.fc_pool(feat))
graph.update_all(fn.copy_src('h', 'm'), fn.max('m', 'neigh'))
h_neigh = graph.ndata['neigh']
elif self._aggre_type == 'lstm':
graph.ndata['h'] = feat
graph.update_all(fn.copy_src('h', 'm'), self._lstm_reducer)
h_neigh = graph.ndata['neigh']
else:
raise KeyError('Aggregator type {} not recognized.'.format(self._aggre_type))
# GraphSAGE GCN does not require fc_self.
if self._aggre_type == 'gcn':
rst = self.fc_neigh(h_neigh)
else:
rst = self.fc_self(h_self) + self.fc_neigh(h_neigh)
# activation
if self.activation is not None:
rst = self.activation(rst)
# normalization
if self.norm is not None:
rst = self.norm(rst)
return rst
class GatedGraphConv(nn.Module):
r"""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} ]
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})
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
n_steps : int
Number of recurrent steps.
n_etypes : int
Number of edge types.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
"""
def __init__(self,
in_feats,
out_feats,
n_steps,
n_etypes,
bias=True):
super(GatedGraphConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._n_steps = n_steps
self.edge_embed = nn.Embedding(n_etypes, out_feats * out_feats)
self.gru = nn.GRUCell(out_feats, out_feats, bias=bias)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = init.calculate_gain('relu')
self.gru.reset_parameters()
init.xavier_normal_(self.edge_embed.weight, gain=gain)
def forward(self, graph, feat, etypes):
"""Compute Gated Graph Convolution layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, D_{in})` where :math:`N`
is the number of nodes of the graph and :math:`D_{in}` is the
input feature size.
etypes : torch.LongTensor
The edge type tensor of shape :math:`(E,)` where :math:`E` is
the number of edges of the graph.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is the output feature size.
"""
graph = graph.local_var()
zero_pad = feat.new_zeros((feat.shape[0], self._out_feats - feat.shape[1]))
feat = th.cat([feat, zero_pad], -1)
# NOTE(zihao): there is still room to optimize, we may do kernel fusion
# for such operations in the future.
graph.edata['w'] = self.edge_embed(etypes).view(-1, self._out_feats, self._out_feats)
for _ in range(self._n_steps):
graph.ndata['h'] = feat.unsqueeze(-1) # (N, D, 1)
graph.update_all(fn.u_mul_e('h', 'w', 'm'),
fn.sum('m', 'a'))
a = graph.ndata.pop('a').sum(dim=1) # (N, D)
feat = self.gru(a, feat)
return feat
class GMMConv(nn.Module):
r"""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}
\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)
Parameters
----------
in_feats : int
Number of input features.
out_feats : int
Number of output features.
dim : int
Dimensionality of pseudo-coordinte.
n_kernels : int
Number of kernels :math:`K`.
aggregator_type : str
Aggregator type (``sum``, ``mean``, ``max``).
residual : bool
If True, use residual connection inside this layer.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
"""
def __init__(self,
in_feats,
out_feats,
dim,
n_kernels,
aggregator_type,
residual=True,
bias=True):
super(GMMConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._dim = dim
self._n_kernels = n_kernels
if aggregator_type == 'sum':
self._reducer = fn.sum
elif aggregator_type == 'mean':
self._reducer = fn.mean
elif aggregator_type == 'max':
self._reducer = fn.max
else:
raise KeyError("Aggregator type {} not recognized.".format(aggregator_type))
self.mu = nn.Parameter(th.Tensor(n_kernels, dim))
self.inv_sigma = nn.Parameter(th.Tensor(n_kernels, dim))
self.fc = nn.Linear(in_feats, n_kernels * out_feats, bias=False)
if residual:
if in_feats != out_feats:
self.res_fc = nn.Linear(in_feats, out_feats, bias=False)
else:
self.res_fc = Identity()
else:
self.register_buffer('res_fc', None)
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = init.calculate_gain('relu')
init.xavier_normal_(self.fc.weight, gain=gain)
if isinstance(self.res_fc, nn.Linear):
init.xavier_normal_(self.res_fc.weight, gain=gain)
init.normal_(self.mu.data, 0, 0.1)
init.normal_(self.inv_sigma.data, 1, 0.1)
if self.bias is not None:
init.zeros_(self.bias.data)
def forward(self, graph, feat, pseudo):
"""Compute Gaussian Mixture Model Convolution layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, D_{in})` where :math:`N`
is the number of nodes of the graph and :math:`D_{in}` is the
input feature size.
pseudo : torch.Tensor
The pseudo coordinate tensor of shape :math:`(E, D_{u})` where
:math:`E` is the number of edges of the graph and :math:`D_{u}`
is the dimensionality of pseudo coordinate.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is the output feature size.
"""
graph = graph.local_var()
graph.ndata['h'] = self.fc(feat).view(-1, self._n_kernels, self._out_feats)
E = graph.number_of_edges()
# compute gaussian weight
gaussian = -0.5 * ((pseudo.view(E, 1, self._dim) -
self.mu.view(1, self._n_kernels, self._dim)) ** 2)
gaussian = gaussian * (self.inv_sigma.view(1, self._n_kernels, self._dim) ** 2)
gaussian = th.exp(gaussian.sum(dim=-1, keepdim=True)) # (E, K, 1)
graph.edata['w'] = gaussian
graph.update_all(fn.u_mul_e('h', 'w', 'm'), self._reducer('m', 'h'))
rst = graph.ndata['h'].sum(1)
# residual connection
if self.res_fc is not None:
rst = rst + self.res_fc(feat)
# bias
if self.bias is not None:
rst = rst + self.bias
return rst
class GINConv(nn.Module):
r"""Graph Isomorphism Network layer from paper `How Powerful are Graph
Neural Networks? <https://arxiv.org/pdf/1810.00826.pdf>`__.
.. math::
h_i^{(l+1)} = f_\Theta \left((1 + \epsilon) h_i^{l} +
\mathrm{aggregate}\left(\left\{h_j^{l}, j\in\mathcal{N}(i)
\right\}\right)\right)
Parameters
----------
apply_func : callable activation function/layer or None
If not None, apply this function to the updated node feature,
the :math:`f_\Theta` in the formula.
aggregator_type : str
Aggregator type to use (``sum``, ``max`` or ``mean``).
init_eps : float, optional
Initial :math:`\epsilon` value, default: ``0``.
learn_eps : bool, optional
If True, :math:`\epsilon` will be a learnable parameter.
"""
def __init__(self,
apply_func,
aggregator_type,
init_eps=0,
learn_eps=False):
super(GINConv, self).__init__()
self.apply_func = apply_func
if aggregator_type == 'sum':
self._reducer = fn.sum
elif aggregator_type == 'max':
self._reducer = fn.max
elif aggregator_type == 'mean':
self._reducer = fn.mean
else:
raise KeyError('Aggregator type {} not recognized.'.format(aggregator_type))
# to specify whether eps is trainable or not.
if learn_eps:
self.eps = th.nn.Parameter(th.FloatTensor([init_eps]))
else:
self.register_buffer('eps', th.FloatTensor([init_eps]))
def forward(self, graph, feat):
r"""Compute Graph Isomorphism Network layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, D)` where :math:`D`
could be any positive integer, :math:`N` is the number
of nodes. If ``apply_func`` is not None, :math:`D` should
fit the input dimensionality requirement of ``apply_func``.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where
: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.
"""
graph = graph.local_var()
graph.ndata['h'] = feat
graph.update_all(fn.copy_u('h', 'm'), self._reducer('m', 'neigh'))
rst = (1 + self.eps) * feat + graph.ndata['neigh']
if self.apply_func is not None:
rst = self.apply_func(rst)
return rst
class ChebConv(nn.Module):
r"""Chebyshev Spectral Graph Convolution layer from paper `Convolutional
Neural Networks on Graphs with Fast Localized Spectral Filtering
<https://arxiv.org/pdf/1606.09375.pdf>`__.
.. math::
h_i^{l+1} &= \sum_{k=0}^{K-1} W^{k, l}z_i^{k, l}
Z^{0, l} &= H^{l}
Z^{1, l} &= \hat{L} \cdot H^{l}
Z^{k, l} &= 2 \cdot \hat{L} \cdot Z^{k-1, l} - Z^{k-2, l}
\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.
out_feats: int
Number of output features.
k : int
Chebyshev filter size.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
"""
def __init__(self,
in_feats,
out_feats,
k,
bias=True):
super(ChebConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self.fc = nn.ModuleList([
nn.Linear(in_feats, out_feats, bias=False) for _ in range(k)
])
self._k = k
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
if self.bias is not None:
init.zeros_(self.bias)
for module in self.fc.modules():
if isinstance(module, nn.Linear):
init.xavier_normal_(module.weight, init.calculate_gain('relu'))
if module.bias is not None:
init.zeros_(module.bias)
def forward(self, graph, feat, lambda_max=None):
r"""Compute ChebNet layer.
Parameters
----------
graph : DGLGraph or BatchedDGLGraph
The graph.
feat : torch.Tensor
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.
lambda_max : list or tensor or None, optional.
A list(tensor) with length :math:`B`, stores the largest eigenvalue
of the normalized laplacian of each individual graph in ``graph``,
where :math:`B` is the batch size of the input graph. Default: None.
If None, this method would compute the list by calling
``dgl.laplacian_lambda_max``.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
with graph.local_scope():
norm = th.pow(
graph.in_degrees().float().clamp(min=1), -0.5).unsqueeze(-1).to(feat.device)
if lambda_max is None:
lambda_max = laplacian_lambda_max(graph)
if isinstance(lambda_max, list):
lambda_max = th.Tensor(lambda_max).to(feat.device)
if lambda_max.dim() < 1:
lambda_max = lambda_max.unsqueeze(-1) # (B,) to (B, 1)
# broadcast from (B, 1) to (N, 1)
lambda_max = broadcast_nodes(graph, lambda_max)
# T0(X)
Tx_0 = feat
rst = self.fc[0](Tx_0)
# T1(X)
if self._k > 1:
graph.ndata['h'] = Tx_0 * norm
graph.update_all(fn.copy_u('h', 'm'), fn.sum('m', 'h'))
h = graph.ndata.pop('h') * norm
# Λ = 2 * (I - D ^ -1/2 A D ^ -1/2) / lambda_max - I
# = - 2(D ^ -1/2 A D ^ -1/2) / lambda_max + (2 / lambda_max - 1) I
Tx_1 = -2. * h / lambda_max + Tx_0 * (2. / lambda_max - 1)
rst = rst + self.fc[1](Tx_1)
# Ti(x), i = 2...k
for i in range(2, self._k):
graph.ndata['h'] = Tx_1 * norm
graph.update_all(fn.copy_u('h', 'm'), fn.sum('m', 'h'))
h = graph.ndata.pop('h') * norm
# Tx_k = 2 * Λ * Tx_(k-1) - Tx_(k-2)
# = - 4(D ^ -1/2 A D ^ -1/2) / lambda_max Tx_(k-1) +
# (4 / lambda_max - 2) Tx_(k-1) -
# Tx_(k-2)
Tx_2 = -4. * h / lambda_max + Tx_1 * (4. / lambda_max - 2) - Tx_0
rst = rst + self.fc[i](Tx_2)
Tx_1, Tx_0 = Tx_2, Tx_1
# add bias
if self.bias is not None:
rst = rst + self.bias
return rst
class SGConv(nn.Module):
r"""Simplifying Graph Convolution layer from paper `Simplifying Graph
Convolutional Networks <https://arxiv.org/pdf/1902.07153.pdf>`__.
.. math::
H^{l+1} = (\hat{D}^{-1/2} \hat{A} \hat{D}^{-1/2})^K H^{l} \Theta^{l}
Parameters
----------
in_feats : int
Number of input features.
out_feats : int
Number of output features.
k : int
Number of hops :math:`K`. Defaults:``1``.
cached : bool
If True, the module would cache
.. math::
(\hat{D}^{-\frac{1}{2}}\hat{A}\hat{D}^{-\frac{1}{2}})^K X\Theta
at the first forward call. This parameter should only be set to
``True`` in Transductive Learning setting.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
norm : callable activation function/layer or None, optional
If not None, applies normalization oto the updated node features.
"""
def __init__(self,
in_feats,
out_feats,
k=1,
cached=False,
bias=True,
norm=None):
super(SGConv, self).__init__()
self.fc = nn.Linear(in_feats, out_feats, bias=bias)
self._cached = cached
self._cached_h = None
self._k = k
self.norm = norm
def forward(self, graph, feat):
r"""Compute Simplifying Graph Convolution layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
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.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
Notes
-----
If ``cache`` is se to True, ``feat`` and ``graph`` should not change during
training, or you will get wrong results.
"""
graph = graph.local_var()
if self._cached_h is not None:
feat = self._cached_h
else:
# compute normalization
degs = graph.in_degrees().float().clamp(min=1)
norm = th.pow(degs, -0.5)
norm[th.isinf(norm)] = 0
norm = norm.to(feat.device).unsqueeze(1)
# compute (D^-1 A D) X
for _ in range(self._k):
feat = feat * norm
graph.ndata['h'] = feat
graph.update_all(fn.copy_u('h', 'm'),
fn.sum('m', 'h'))
feat = graph.ndata.pop('h')
feat = feat * norm
if self.norm is not None:
feat = self.norm(feat)
# cache feature
if self._cached:
self._cached_h = feat
return self.fc(feat)
class NNConv(nn.Module):
r"""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)
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
edge_func : callable activation function/layer
Maps each edge feature to a vector of shape
``(in_feats * out_feats)`` as weight to compute
messages.
Also is the :math:`f_\Theta` in the formula.
aggregator_type : str
Aggregator type to use (``sum``, ``mean`` or ``max``).
residual : bool, optional
If True, use residual connection. Default: ``False``.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
"""
def __init__(self,
in_feats,
out_feats,
edge_func,
aggregator_type,
residual=False,
bias=True):
super(NNConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self.edge_nn = edge_func
if aggregator_type == 'sum':
self.reducer = fn.sum
elif aggregator_type == 'mean':
self.reducer = fn.mean
elif aggregator_type == 'max':
self.reducer = fn.max
else:
raise KeyError('Aggregator type {} not recognized: '.format(aggregator_type))
self._aggre_type = aggregator_type
if residual:
if in_feats != out_feats:
self.res_fc = nn.Linear(in_feats, out_feats, bias=False)
else:
self.res_fc = Identity()
else:
self.register_buffer('res_fc', None)
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
gain = init.calculate_gain('relu')
if self.bias is not None:
nn.init.zeros_(self.bias)
if isinstance(self.res_fc, nn.Linear):
nn.init.xavier_normal_(self.res_fc.weight, gain=gain)
def forward(self, graph, feat, efeat):
r"""Compute MPNN Graph Convolution layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, D_{in})` where :math:`N`
is the number of nodes of the graph and :math:`D_{in}` is the
input feature size.
efeat : torch.Tensor
The edge feature of shape :math:`(N, *)`, should fit the input
shape requirement of ``edge_nn``.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is the output feature size.
"""
graph = graph.local_var()
# (n, d_in, 1)
graph.ndata['h'] = feat.unsqueeze(-1)
# (n, d_in, d_out)
graph.edata['w'] = self.edge_nn(efeat).view(-1, self._in_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.ndata.pop('neigh').sum(dim=1) # (n, d_out)
# residual connection
if self.res_fc is not None:
rst = rst + self.res_fc(feat)
# bias
if self.bias is not None:
rst = rst + self.bias
return rst
class APPNPConv(nn.Module):
r"""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^{t+1} & = (1-\alpha)\left(\hat{D}^{-1/2}
\hat{A} \hat{D}^{-1/2} H^{t} + \alpha H^{0}\right)
Parameters
----------
k : int
Number of iterations :math:`K`.
alpha : float
The teleport probability :math:`\alpha`.
edge_drop : float, optional
Dropout rate on edges that controls the
messages received by each node. Default: ``0``.
"""
def __init__(self,
k,
alpha,
edge_drop=0.):
super(APPNPConv, self).__init__()
self._k = k
self._alpha = alpha
self.edge_drop = nn.Dropout(edge_drop) if edge_drop > 0 else Identity()
def forward(self, graph, feat):
r"""Compute APPNP layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, *)` :math:`N` is the
number of nodes, and :math:`*` could be of any shape.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, *)` where :math:`*`
should be the same as input shape.
"""
graph = graph.local_var()
norm = th.pow(graph.in_degrees().float().clamp(min=1), -0.5)
norm = norm.unsqueeze(-1).to(feat.device)
feat_0 = feat
for _ in range(self._k):
# normalization by src
feat = feat * norm
graph.ndata['h'] = feat
graph.edata['w'] = self.edge_drop(
th.ones(graph.number_of_edges(), 1).to(feat.device))
graph.update_all(fn.u_mul_e('h', 'w', 'm'),
fn.sum('m', 'h'))
feat = graph.ndata.pop('h')
# normalization by dst
feat = feat * norm
feat = (1 - self._alpha) * feat + self._alpha * feat_0
return feat
class AGNNConv(nn.Module):
r"""Attention-based Graph Neural Network layer from paper `Attention-based
Graph Neural Network for Semi-Supervised Learning
<https://arxiv.org/abs/1803.03735>`__.
.. math::
H^{l+1} = P H^{l}
where :math:`P` is computed as:
.. math::
P_{ij} = \mathrm{softmax}_i ( \beta \cdot \cos(h_i^l, h_j^l))
Parameters
----------
init_beta : float, optional
The :math:`\beta` in the formula.
learn_beta : bool, optional
If True, :math:`\beta` will be learnable parameter.
"""
def __init__(self,
init_beta=1.,
learn_beta=True):
super(AGNNConv, self).__init__()
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.
Parameters
----------
graph : DGLGraph
The graph.
feat : torch.Tensor
The input feature of shape :math:`(N, *)` :math:`N` is the
number of nodes, and :math:`*` could be of any shape.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, *)` where :math:`*`
should be the same as input shape.
"""
graph = graph.local_var()
graph.ndata['h'] = feat
graph.ndata['norm_h'] = F.normalize(feat, p=2, dim=-1)
# compute cosine distance
graph.apply_edges(fn.u_mul_v('norm_h', 'norm_h', 'cos'))
cos = graph.edata.pop('cos').sum(-1)
e = self.beta * cos
graph.edata['p'] = edge_softmax(graph, e)
graph.update_all(fn.u_mul_e('h', 'p', 'm'), fn.sum('m', 'h'))
return graph.ndata.pop('h')
class DenseGraphConv(nn.Module):
"""Graph Convolutional Network layer where the graph structure
is given by an adjacency matrix.
We recommend user to use this module when inducing graph convolution
on dense graphs / k-hop graphs.
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
norm : bool
If True, the normalizer :math:`c_{ij}` is applied. Default: ``True``.
bias : bool
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``.
See also
--------
GraphConv
"""
def __init__(self,
in_feats,
out_feats,
norm=True,
bias=True,
activation=None):
super(DenseGraphConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._norm = norm
self.weight = nn.Parameter(th.Tensor(in_feats, out_feats))
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self.reset_parameters()
self._activation = activation
def reset_parameters(self):
"""Reinitialize learnable parameters."""
init.xavier_uniform_(self.weight)
if self.bias is not None:
init.zeros_(self.bias)
def forward(self, adj, feat):
r"""Compute (Dense) Graph Convolution layer.
Parameters
----------
adj : torch.Tensor
The adjacency matrix of the graph to apply Graph Convolution on,
should be of shape :math:`(N, N)`, where a row represents the destination
and a column represents the source.
feat : torch.Tensor
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.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
adj = adj.float().to(feat.device)
if self._norm:
in_degrees = adj.sum(dim=1)
norm = th.pow(in_degrees, -0.5)
shp = norm.shape + (1,) * (feat.dim() - 1)
norm = th.reshape(norm, shp).to(feat.device)
feat = feat * norm
if self._in_feats > self._out_feats:
# mult W first to reduce the feature size for aggregation.
feat = th.matmul(feat, self.weight)
rst = adj @ feat
else:
# aggregate first then mult W
rst = adj @ feat
rst = th.matmul(rst, self.weight)
if self._norm:
rst = rst * norm
if self.bias is not None:
rst = rst + self.bias
if self._activation is not None:
rst = self._activation(rst)
return rst
class DenseSAGEConv(nn.Module):
"""GraphSAGE layer where the graph structure is given by an
adjacency matrix.
We recommend to use this module when inducing GraphSAGE operations
on dense graphs / k-hop graphs.
Note that we only support gcn aggregator in DenseSAGEConv.
Parameters
----------
in_feats : int
Input feature size.
out_feats : int
Output feature size.
feat_drop : float, optional
Dropout rate on features. Default: 0.
bias : bool
If True, adds a learnable bias to the output. Default: ``True``.
norm : callable activation function/layer or None, optional
If not None, applies normalization oto the updated node features.
activation : callable activation function/layer or None, optional
If not None, applies an activation function to the updated node features.
Default: ``None``.
See also
--------
SAGEConv
"""
def __init__(self,
in_feats,
out_feats,
feat_drop=0.,
bias=True,
norm=None,
activation=None):
super(DenseSAGEConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._norm = norm
self.feat_drop = nn.Dropout(feat_drop)
self.activation = activation
self.fc = nn.Linear(in_feats, out_feats, bias=bias)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
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.
Parameters
----------
adj : torch.Tensor
The adjacency matrix of the graph to apply Graph Convolution on,
should be of shape :math:`(N, N)`, where a row represents the destination
and a column represents the source.
feat : torch.Tensor
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.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
adj = adj.float().to(feat.device)
feat = self.feat_drop(feat)
in_degrees = adj.sum(dim=1).unsqueeze(-1)
h_neigh = (adj @ feat + feat) / (in_degrees + 1)
rst = self.fc(h_neigh)
# activation
if self.activation is not None:
rst = self.activation(rst)
# normalization
if self._norm is not None:
rst = self._norm(rst)
return rst
class DenseChebConv(nn.Module):
r"""Chebyshev Spectral Graph Convolution layer from paper `Convolutional
Neural Networks on Graphs with Fast Localized Spectral Filtering
<https://arxiv.org/pdf/1606.09375.pdf>`__.
We recommend to use this module when inducing ChebConv operations on dense
graphs / k-hop graphs.
Parameters
----------
in_feats: int
Number of input features.
out_feats: int
Number of output features.
k : int
Chebyshev filter size.
bias : bool, optional
If True, adds a learnable bias to the output. Default: ``True``.
See also
--------
ChebConv
"""
def __init__(self,
in_feats,
out_feats,
k,
bias=True):
super(DenseChebConv, self).__init__()
self._in_feats = in_feats
self._out_feats = out_feats
self._k = k
self.W = nn.Parameter(th.Tensor(k, in_feats, out_feats))
if bias:
self.bias = nn.Parameter(th.Tensor(out_feats))
else:
self.register_buffer('bias', None)
self.reset_parameters()
def reset_parameters(self):
"""Reinitialize learnable parameters."""
if self.bias is not None:
init.zeros_(self.bias)
for i in range(self._k):
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.
Parameters
----------
adj : torch.Tensor
The adjacency matrix of the graph to apply Graph Convolution on,
should be of shape :math:`(N, N)`, where a row represents the destination
and a column represents the source.
feat : torch.Tensor
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.
lambda_max : float or None, optional
A float value indicates the largest eigenvalue of given graph.
Default: None.
Returns
-------
torch.Tensor
The output feature of shape :math:`(N, D_{out})` where :math:`D_{out}`
is size of output feature.
"""
A = adj.to(feat)
num_nodes = A.shape[0]
in_degree = 1 / A.sum(dim=1).clamp(min=1).sqrt()
D_invsqrt = th.diag(in_degree)
I = th.eye(num_nodes).to(A)
L = I - D_invsqrt @ A @ D_invsqrt
if lambda_max is None:
lambda_ = th.eig(L)[0][:, 0]
lambda_max = lambda_.max()
L_hat = 2 * L / lambda_max - I
Z = [th.eye(num_nodes).to(A)]
for i in range(1, self._k):
if i == 1:
Z.append(L_hat)
else:
Z.append(2 * L_hat @ Z[-1] - Z[-2])
Zs = th.stack(Z, 0) # (k, n, n)
Zh = (Zs @ feat.unsqueeze(0) @ self.W)
Zh = Zh.sum(0)
if self.bias is not None:
Zh = Zh + self.bias
return Zh