目录
引言
由于图数据结构问题，直接使用Tensorflow的一些层是无法直接处理图数据的，需要借用TF-GNN框架下的MapFeatures对图数据中的节点特征或是边特征进行变换。
题外话(MapFeatures使用)
节点特征变换
from tensorflow.keras.layers import BatchNormalization
from tensorflow_gnn.keras.layers import MapFeatures
# map node features
def node_sets_fn(node_set, *, node_set_name):
features = node_set.features
return BatchNormalization()(features["hidden_state"])
graph = MapFeatures(node_sets_fn=node_sets_fn)(graph)
边特征变换
from tensorflow_gnn.keras.layers import MapFeatures
# Hashes edge features called "id", leaves others unchanged:
def edge_sets_fn(edge_set, *, edge_set_name):
features = edge_set.get_features_dict()
ids = features.pop("id")
num_bins = 100_000 if edge_set_name == "views" else 20_000
hashed_ids = tf.keras.layers.Hashing(num_bins=num_bins)(ids)
features["hashed_id"] = hashed_ids
return features
graph = MapFeatures(edge_sets_fn=edge_sets_fn)(graph)
传入额外参数
from functools import partial
from tensorflow.keras.layers import Dense
from tensorflow_gnn.keras.layers import MapFeatures
# map node features
def node_sets_fn(node_set, *, node_set_name, dim):
features = node_set.features
return Dense(dim)(features["hidden_state"])
graph = MapFeatures(node_sets_fn=partial(node_sets_fn, dim=64))(graph)
问题
就是在使用MapFeatures时，如果循环使用则会在存储模型的时候报错：ValueError: Unable to create dataset (name already exists)
问题demo
from functools import partial
from tensorflow.keras.layers import Dense
from tensorflow_gnn.keras.layers import MapFeatures
# map node features
def node_sets_fn(node_set, *, node_set_name, dim):
features = node_set.features
return Dense(dim)(features["hidden_state"])
for ln in range(layer_num):
graph = MapFeatures(node_sets_fn=partial(node_sets_fn, dim=64))(graph)
解决方案
最后发现是在使用MapFeatures时，使用层时如Dense需要区分每一次变换时的层名
from functools import partial
from tensorflow.keras.layers import Dense
from tensorflow_gnn.keras.layers import MapFeatures
# map node features
def node_sets_fn(node_set, *, node_set_name, dim，name):
features = node_set.features
return Dense(dim, name=f'Dense_{name}')(features["hidden_state"])
for ln in range(layer_num):
graph = MapFeatures(node_sets_fn=partial(node_sets_fn, dim=64，name=ln))(graph)