Source code for cogdl.models.emb.dgk

import hashlib

import torch
from joblib import Parallel, delayed
import networkx as nx
import numpy as np
from gensim.models.word2vec import Word2Vec
from .. import BaseModel

[docs]class DeepGraphKernel(BaseModel): r"""The Hin2vec model from the `"Deep Graph Kernels" <>`_ paper. Args: hidden_size (int) : The dimension of node representation. min_count (int) : Parameter in word2vec. window (int) : The actual context size which is considered in language model. sampling_rate (float) : Parameter in word2vec. iteration (int) : The number of iteration in WL method. epochs (int) : The number of training iteration. alpha (float) : The learning rate of word2vec. """
[docs] @staticmethod def add_args(parser): parser.add_argument("--hidden-size", type=int, default=128) parser.add_argument("--window_size", type=int, default=5) parser.add_argument("--min-count", type=int, default=1) parser.add_argument("--sampling", type=float, default=0.0001) parser.add_argument("--iteration", type=int, default=2) parser.add_argument("--epochs", type=int, default=20) parser.add_argument("--alpha", type=float, default=0.01)
[docs] @classmethod def build_model_from_args(cls, args): return cls( args.hidden_size, args.min_count, args.window_size, args.sampling, args.iteration, args.epochs, args.alpha )
[docs] @staticmethod def feature_extractor(data, rounds, name): edge_index = torch.stack(data.edge_index) graph = nx.from_edgelist(np.array(edge_index.T.cpu(), dtype=int)) if data.x is not None: feature = {int(key): str(val.argmax(axis=0)) for key, val in enumerate(np.array(data.x.cpu()))} else: feature = dict( graph_wl_features = DeepGraphKernel.wl_iterations(graph, feature, rounds) return graph_wl_features
[docs] @staticmethod def wl_iterations(graph, features, rounds): # TODO: solve hash and number nodes = graph.nodes wl_features = [str(val) for _, val in features.items()] for i in range(rounds): new_feats = {} for node in nodes: neighbors = graph.neighbors(node) neigh_feats = [features[x] for x in neighbors] neigh_feats = [features[node]] + sorted(neigh_feats) hash_feat = hashlib.md5("_".join([str(x) for x in neigh_feats]).encode()) hash_feat = hash_feat.hexdigest() new_feats[node] = hash_feat wl_features = wl_features + list(new_feats.values()) features = new_feats return wl_features
def __init__(self, hidden_dim, min_count, window_size, sampling_rate, rounds, epochs, alpha, n_workers=4): super(DeepGraphKernel, self).__init__() self.hidden_dim = hidden_dim self.min_count = min_count self.window = window_size self.sampling_rate = sampling_rate self.n_workers = n_workers self.rounds = rounds self.model = None self.gl_collections = None self.epochs = epochs self.alpha = alpha
[docs] def forward(self, graphs, **kwargs): if self.gl_collections is None: self.gl_collections = Parallel(n_jobs=self.n_workers)( delayed(DeepGraphKernel.feature_extractor)(graph, self.rounds, str(i)) for i, graph in enumerate(graphs) ) model = Word2Vec( self.gl_collections, vector_size=self.hidden_dim, window=self.window, min_count=self.min_count, sample=self.sampling_rate, workers=self.n_workers, epochs=self.epochs, alpha=self.alpha, ) vectors = np.asarray([model.wv[str(node)] for node in model.wv.index_to_key]) S = node2id = dict(zip(model.wv.index_to_key, range(len(model.wv.index_to_key)))) num_graph, size_vocab = len(graphs), len(node2id) norm_prob = np.zeros((num_graph, size_vocab)) for i, gls in enumerate(self.gl_collections): for gl in gls: if gl in node2id: norm_prob[i, node2id[gl]] += 1 # norm_prob[i] /= sum(norm_prob[i]) embedding = return embedding
[docs] def save_embedding(self, output_path):"model.wv") self.model.wv.save_word2vec_format("model.emb")