Merge pull request #38 from Liwb5/develop

add gin layer

Author: Liwb5

ogb_examples/linkproppred/main_pgl.py

@@ -96,7 +96,7 @@ def forward(self, graph):
 
         loss = fluid.layers.sigmoid_cross_entropy_with_logits(pred,
                                                               self.edge_label)
-        loss = fluid.layers.reduce_mean(loss)
+        loss = fluid.layers.reduce_sum(loss)
 
         return pred, prob, loss
 
@@ -223,8 +223,10 @@ def test(exe, val_program, prob, evaluator, feed, splitted_edge):
         "float32").reshape(-1, 1)
     y_pred = exe.run(val_program, feed=feed, fetch_list=[prob])[0]
     input_dict = {
-        "y_true": splitted_edge["valid_edge_label"],
-        "y_pred": y_pred.reshape(-1, ),
+        "y_pred_pos":
+        y_pred[splitted_edge["valid_edge_label"] == 1].reshape(-1, ),
+        "y_pred_neg":
+        y_pred[splitted_edge["valid_edge_label"] == 0].reshape(-1, )
     }
     result["valid"] = evaluator.eval(input_dict)
 
@@ -234,8 +236,10 @@ def test(exe, val_program, prob, evaluator, feed, splitted_edge):
         "float32").reshape(-1, 1)
     y_pred = exe.run(val_program, feed=feed, fetch_list=[prob])[0]
     input_dict = {
-        "y_true": splitted_edge["test_edge_label"],
-        "y_pred": y_pred.reshape(-1, ),
+        "y_pred_pos":
+        y_pred[splitted_edge["test_edge_label"] == 1].reshape(-1, ),
+        "y_pred_neg":
+        y_pred[splitted_edge["test_edge_label"] == 0].reshape(-1, )
     }
     result["test"] = evaluator.eval(input_dict)
     return result

pgl/layers/conv.py

@@ -18,7 +18,7 @@
 from pgl import graph_wrapper
 from pgl.utils import paddle_helper
 
-__all__ = ['gcn', 'gat']
+__all__ = ['gcn', 'gat', 'gin']
 
 
 def gcn(gw, feature, hidden_size, activation, name, norm=None):
@@ -178,3 +178,73 @@ def reduce_attention(msg):
     bias.stop_gradient = True
     output = fluid.layers.elementwise_add(output, bias, act=activation)
     return output
+
+
+def gin(gw,
+        feature,
+        hidden_size,
+        activation,
+        name,
+        init_eps=0.0,
+        train_eps=False):
+    """Implementation of Graph Isomorphism Network (GIN) layer.
+
+    This is an implementation of the paper How Powerful are Graph Neural Networks?
+    (https://arxiv.org/pdf/1810.00826.pdf).
+
+    In their implementation, all MLPs have 2 layers. Batch normalization is applied
+    on every hidden layer.
+
+    Args:
+        gw: Graph wrapper object (:code:`StaticGraphWrapper` or :code:`GraphWrapper`)
+
+        feature: A tensor with shape (num_nodes, feature_size).
+
+        name: GIN layer names.
+
+        hidden_size: The hidden size for gin.
+
+        activation: The activation for the output.
+
+        init_eps: float, optional
+            Initial :math:`\epsilon` value, default is 0.
+
+        train_eps: bool, optional
+            if True, :math:`\epsilon` will be a learnable parameter.
+
+    Return:
+        A tensor with shape (num_nodes, hidden_size).
+    """
+
+    def send_src_copy(src_feat, dst_feat, edge_feat):
+        return src_feat["h"]
+
+    epsilon = fluid.layers.create_parameter(
+        shape=[1, 1],
+        dtype="float32",
+        attr=fluid.ParamAttr(name="%s_eps" % name),
+        default_initializer=fluid.initializer.ConstantInitializer(
+            value=init_eps))
+
+    if not train_eps:
+        epsilon.stop_gradient = True
+
+    msg = gw.send(send_src_copy, nfeat_list=[("h", feature)])
+    output = gw.recv(msg, "sum") + (1.0 + epsilon) * feature
+
+    output = fluid.layers.fc(output,
+                             size=hidden_size,
+                             act=None,
+                             param_attr=fluid.ParamAttr(name="%s_w_0" % name),
+                             bias_attr=fluid.ParamAttr(name="%s_b_0" % name))
+
+    output = fluid.layers.batch_norm(output)
+    output = getattr(fluid.layers, activation)(output)
+
+    output = fluid.layers.fc(output,
+                             size=hidden_size,
+                             act=activation,
+                             param_attr=fluid.ParamAttr(name="%s_w_1" % name),
+                             bias_attr=fluid.ParamAttr(name="%s_b_1" % name))
+
+    return output

pgl/tests/test_gin.py

@@ -0,0 +1,82 @@
+# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+    This file is for testing gin layer.
+"""
+from __future__ import division
+from __future__ import absolute_import
+from __future__ import print_function
+from __future__ import unicode_literals
+import unittest
+import numpy as np
+
+import paddle.fluid as F
+import paddle.fluid.layers as L
+
+from pgl.layers.conv import gin
+from pgl import graph
+from pgl import graph_wrapper
+
+
+class GinTest(unittest.TestCase):
+    """GinTest
+    """
+
+    def test_gin(self):
+        """test_gin
+        """
+        np.random.seed(1)
+        hidden_size = 8
+
+        num_nodes = 10
+
+        edges = [(1, 4), (0, 5), (1, 9), (1, 8), (2, 8), (2, 5), (3, 6),
+                 (3, 7), (3, 4), (3, 8)]
+        inver_edges = [(v, u) for u, v in edges]
+        edges.extend(inver_edges)
+
+        node_feat = {"feature": np.random.rand(10, 4).astype("float32")}
+
+        g = graph.Graph(num_nodes=num_nodes, edges=edges, node_feat=node_feat)
+
+        use_cuda = False
+        place = F.GPUPlace(0) if use_cuda else F.CPUPlace()
+
+        prog = F.Program()
+        startup_prog = F.Program()
+        with F.program_guard(prog, startup_prog):
+            gw = graph_wrapper.GraphWrapper(
+                name='graph',
+                place=place,
+                node_feat=g.node_feat_info(),
+                edge_feat=g.edge_feat_info())
+
+            output = gin(gw,
+                         gw.node_feat['feature'],
+                         hidden_size=hidden_size,
+                         activation='relu',
+                         name='gin',
+                         init_eps=1,
+                         train_eps=True)
+
+        exe = F.Executor(place)
+        exe.run(startup_prog)
+        ret = exe.run(prog, feed=gw.to_feed(g), fetch_list=[output])
+
+        self.assertEqual(ret[0].shape[0], num_nodes)
+        self.assertEqual(ret[0].shape[1], hidden_size)
+
+
+if __name__ == "__main__":
+    unittest.main()