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Zihao Ye af61e2fbb4 [Feature] Support nn modules for bipartite graphs. (#1392)
* init gat

* fix

* gin

* 7 nn modules

* rename & lint

* upd

* upd

* fix lint

* upd test

* upd

* lint

* shape check

* upd

* lint

* address comments

* update tensorflow

Co-authored-by: Quan Gan <coin2028@hotmail.com>
Co-authored-by: Jinjing Zhou <VoVAllen@users.noreply.github.com>
Co-authored-by: Minjie Wang <wmjlyjemaine@gmail.com>
2020-03-29 16:48:38 +08:00

85 行
3.2 KiB
Python

"""MXNet Module for Graph Isomorphism Network layer"""
# pylint: disable= no-member, arguments-differ, invalid-name
import mxnet as mx
from mxnet.gluon import nn
from .... import function as fn
from ....utils import expand_as_pair
class GINConv(nn.Block):
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__()
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))
with self.name_scope():
self.apply_func = apply_func
self.eps = self.params.get('eps',
shape=(1,),
grad_req='write' if learn_eps else 'null',
init=mx.init.Constant(init_eps))
def forward(self, graph, feat):
r"""Compute Graph Isomorphism Network layer.
Parameters
----------
graph : DGLGraph
The graph.
feat : mxnet.NDArray or a pair of mxnet.NDArray
If a mxnet.NDArray is given, 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 mxnet.NDArray is given, the pair must contain two tensors of
shape :math:`(N_{in}, D_{in})` and :math:`(N_{out}, D_{in})`.
If ``apply_func`` is not None, :math:`D_{in}` should
fit the input dimensionality requirement of ``apply_func``.
Returns
-------
mxnet.NDArray
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()
feat_src, feat_dst = expand_as_pair(feat)
graph.srcdata['h'] = feat_src
graph.update_all(fn.copy_u('h', 'm'), self._reducer('m', 'neigh'))
rst = (1 + self.eps.data(feat_dst.context)) * feat_dst + graph.dstdata['neigh']
if self.apply_func is not None:
rst = self.apply_func(rst)
return rst