| @@ -0,0 +1,322 @@ | |||||
| #!/usr/bin/env python3 | |||||
| # -*- coding: utf-8 -*- | |||||
| """ | |||||
| Created on Thu Aug 20 16:09:51 2020 | |||||
| @author: ljia | |||||
| @references: | |||||
| [1] S Vichy N Vishwanathan, Nicol N Schraudolph, Risi Kondor, and Karsten M Borgwardt. Graph kernels. Journal of Machine Learning Research, 11(Apr):1201–1242, 2010. | |||||
| """ | |||||
| import sys | |||||
| from tqdm import tqdm | |||||
| import numpy as np | |||||
| import networkx as nx | |||||
| from scipy.sparse import identity | |||||
| from scipy.sparse.linalg import cg | |||||
| from gklearn.utils.parallel import parallel_gm, parallel_me | |||||
| from gklearn.kernels import RandomWalkMeta | |||||
| from gklearn.utils.utils import compute_vertex_kernels | |||||
| class ConjugateGradient(RandomWalkMeta): | |||||
| def __init__(self, **kwargs): | |||||
| super().__init__(**kwargs) | |||||
| self._node_kernels = kwargs.get('node_kernels', None) | |||||
| self._edge_kernels = kwargs.get('edge_kernels', None) | |||||
| self._node_labels = kwargs.get('node_labels', []) | |||||
| self._edge_labels = kwargs.get('edge_labels', []) | |||||
| self._node_attrs = kwargs.get('node_attrs', []) | |||||
| self._edge_attrs = kwargs.get('edge_attrs', []) | |||||
| def _compute_gm_series(self): | |||||
| self._check_edge_weight(self._graphs, self._verbose) | |||||
| self._check_graphs(self._graphs) | |||||
| lmda = self._weight | |||||
| # Compute Gram matrix. | |||||
| gram_matrix = np.zeros((len(self._graphs), len(self._graphs))) | |||||
| # Reindex nodes using consecutive integers for the convenience of kernel computation. | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(self._graphs, desc='Reindex vertices', file=sys.stdout) | |||||
| else: | |||||
| iterator = self._graphs | |||||
| self._graphs = [nx.convert_node_labels_to_integers(g, first_label=0, label_attribute='label_orignal') for g in iterator] | |||||
| if self._p is None and self._q is None: # p and q are uniform distributions as default. | |||||
| from itertools import combinations_with_replacement | |||||
| itr = combinations_with_replacement(range(0, len(self._graphs)), 2) | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(itr, desc='Computing kernels', file=sys.stdout) | |||||
| else: | |||||
| iterator = itr | |||||
| for i, j in iterator: | |||||
| kernel = self._kernel_do(self._graphs[i], self._graphs[j], lmda) | |||||
| gram_matrix[i][j] = kernel | |||||
| gram_matrix[j][i] = kernel | |||||
| else: # @todo | |||||
| pass | |||||
| return gram_matrix | |||||
| def _compute_gm_imap_unordered(self): | |||||
| self._check_edge_weight(self._graphs, self._verbose) | |||||
| self._check_graphs(self._graphs) | |||||
| # Compute Gram matrix. | |||||
| gram_matrix = np.zeros((len(self._graphs), len(self._graphs))) | |||||
| # @todo: parallel this. | |||||
| # Reindex nodes using consecutive integers for the convenience of kernel computation. | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(self._graphs, desc='Reindex vertices', file=sys.stdout) | |||||
| else: | |||||
| iterator = self._graphs | |||||
| self._graphs = [nx.convert_node_labels_to_integers(g, first_label=0, label_attribute='label_orignal') for g in iterator] | |||||
| if self._p is None and self._q is None: # p and q are uniform distributions as default. | |||||
| def init_worker(gn_toshare): | |||||
| global G_gn | |||||
| G_gn = gn_toshare | |||||
| do_fun = self._wrapper_kernel_do | |||||
| parallel_gm(do_fun, gram_matrix, self._graphs, init_worker=init_worker, | |||||
| glbv=(self._graphs,), n_jobs=self._n_jobs, verbose=self._verbose) | |||||
| else: # @todo | |||||
| pass | |||||
| return gram_matrix | |||||
| def _compute_kernel_list_series(self, g1, g_list): | |||||
| self._check_edge_weight(g_list + [g1], self._verbose) | |||||
| self._check_graphs(g_list + [g1]) | |||||
| lmda = self._weight | |||||
| # compute kernel list. | |||||
| kernel_list = [None] * len(g_list) | |||||
| # Reindex nodes using consecutive integers for the convenience of kernel computation. | |||||
| g1 = nx.convert_node_labels_to_integers(g1, first_label=0, label_attribute='label_orignal') | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(g_list, desc='Reindex vertices', file=sys.stdout) | |||||
| else: | |||||
| iterator = g_list | |||||
| g_list = [nx.convert_node_labels_to_integers(g, first_label=0, label_attribute='label_orignal') for g in iterator] | |||||
| if self._p is None and self._q is None: # p and q are uniform distributions as default. | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(range(len(g_list)), desc='Computing kernels', file=sys.stdout) | |||||
| else: | |||||
| iterator = range(len(g_list)) | |||||
| for i in iterator: | |||||
| kernel = self._kernel_do(g1, g_list[i], lmda) | |||||
| kernel_list[i] = kernel | |||||
| else: # @todo | |||||
| pass | |||||
| return kernel_list | |||||
| def _compute_kernel_list_imap_unordered(self, g1, g_list): | |||||
| self._check_edge_weight(g_list + [g1], self._verbose) | |||||
| self._check_graphs(g_list + [g1]) | |||||
| # compute kernel list. | |||||
| kernel_list = [None] * len(g_list) | |||||
| # Reindex nodes using consecutive integers for the convenience of kernel computation. | |||||
| g1 = nx.convert_node_labels_to_integers(g1, first_label=0, label_attribute='label_orignal') | |||||
| # @todo: parallel this. | |||||
| if self._verbose >= 2: | |||||
| iterator = tqdm(g_list, desc='Reindex vertices', file=sys.stdout) | |||||
| else: | |||||
| iterator = g_list | |||||
| g_list = [nx.convert_node_labels_to_integers(g, first_label=0, label_attribute='label_orignal') for g in iterator] | |||||
| if self._p is None and self._q is None: # p and q are uniform distributions as default. | |||||
| def init_worker(g1_toshare, g_list_toshare): | |||||
| global G_g1, G_g_list | |||||
| G_g1 = g1_toshare | |||||
| G_g_list = g_list_toshare | |||||
| do_fun = self._wrapper_kernel_list_do | |||||
| def func_assign(result, var_to_assign): | |||||
| var_to_assign[result[0]] = result[1] | |||||
| itr = range(len(g_list)) | |||||
| len_itr = len(g_list) | |||||
| parallel_me(do_fun, func_assign, kernel_list, itr, len_itr=len_itr, | |||||
| init_worker=init_worker, glbv=(g1, g_list), method='imap_unordered', | |||||
| n_jobs=self._n_jobs, itr_desc='Computing kernels', verbose=self._verbose) | |||||
| else: # @todo | |||||
| pass | |||||
| return kernel_list | |||||
| def _wrapper_kernel_list_do(self, itr): | |||||
| return itr, self._kernel_do(G_g1, G_g_list[itr], self._weight) | |||||
| def _compute_single_kernel_series(self, g1, g2): | |||||
| self._check_edge_weight([g1] + [g2], self._verbose) | |||||
| self._check_graphs([g1] + [g2]) | |||||
| lmda = self._weight | |||||
| # Reindex nodes using consecutive integers for the convenience of kernel computation. | |||||
| g1 = nx.convert_node_labels_to_integers(g1, first_label=0, label_attribute='label_orignal') | |||||
| g2 = nx.convert_node_labels_to_integers(g2, first_label=0, label_attribute='label_orignal') | |||||
| if self._p is None and self._q is None: # p and q are uniform distributions as default. | |||||
| kernel = self._kernel_do(g1, g2, lmda) | |||||
| else: # @todo | |||||
| pass | |||||
| return kernel | |||||
| def _kernel_do(self, g1, g2, lmda): | |||||
| # Frist, compute kernels between all pairs of nodes using the method borrowed | |||||
| # from FCSP. It is faster than directly computing all edge kernels | |||||
| # when $d_1d_2>2$, where $d_1$ and $d_2$ are vertex degrees of the | |||||
| # graphs compared, which is the most case we went though. For very | |||||
| # sparse graphs, this would be slow. | |||||
| vk_dict = self._compute_vertex_kernels(g1, g2) | |||||
| # Compute the weight matrix of the direct product graph. | |||||
| w_times, w_dim = self._compute_weight_matrix(g1, g2, vk_dict) | |||||
| # use uniform distribution if there is no prior knowledge. | |||||
| p_times_uni = 1 / w_dim | |||||
| A = identity(w_times.shape[0]) - w_times * lmda | |||||
| b = np.full((w_dim, 1), p_times_uni) | |||||
| x, _ = cg(A, b) | |||||
| # use uniform distribution if there is no prior knowledge. | |||||
| q_times = np.full((1, w_dim), p_times_uni) | |||||
| return np.dot(q_times, x) | |||||
| def _wrapper_kernel_do(self, itr): | |||||
| i = itr[0] | |||||
| j = itr[1] | |||||
| return i, j, self._kernel_do(G_gn[i], G_gn[j], self._weight) | |||||
| def _func_fp(x, p_times, lmda, w_times): | |||||
| haha = w_times * x | |||||
| haha = lmda * haha | |||||
| haha = p_times + haha | |||||
| return p_times + lmda * np.dot(w_times, x) | |||||
| def _compute_vertex_kernels(self, g1, g2): | |||||
| """Compute vertex kernels between vertices of two graphs. | |||||
| """ | |||||
| return compute_vertex_kernels(g1, g2, self._node_kernels, node_labels=self._node_labels, node_attrs=self._node_attrs) | |||||
| # @todo: move if out to make it faster. | |||||
| # @todo: node/edge kernels use direct function rather than dicts. | |||||
| def _compute_weight_matrix(self, g1, g2, vk_dict): | |||||
| """Compute the weight matrix of the direct product graph. | |||||
| """ | |||||
| # Define edge kernels. | |||||
| def compute_ek_11(e1, e2, ke): | |||||
| e1_labels = [e1[2][el] for el in self._edge_labels] | |||||
| e2_labels = [e2[2][el] for el in self._edge_labels] | |||||
| e1_attrs = [e1[2][ea] for ea in self._edge_attrs] | |||||
| e2_attrs = [e2[2][ea] for ea in self._edge_attrs] | |||||
| return ke(e1_labels, e2_labels, e1_attrs, e2_attrs) | |||||
| def compute_ek_10(e1, e2, ke): | |||||
| e1_labels = [e1[2][el] for el in self._edge_labels] | |||||
| e2_labels = [e2[2][el] for el in self._edge_labels] | |||||
| return ke(e1_labels, e2_labels) | |||||
| def compute_ek_01(e1, e2, ke): | |||||
| e1_attrs = [e1[2][ea] for ea in self._edge_attrs] | |||||
| e2_attrs = [e2[2][ea] for ea in self._edge_attrs] | |||||
| return ke(e1_attrs, e2_attrs) | |||||
| def compute_ek_00(e1, e2, ke): | |||||
| return 1 | |||||
| # Select the proper edge kernel. | |||||
| if len(self._edge_labels) > 0: | |||||
| # edge symb and non-synb labeled | |||||
| if len(self._edge_attrs) > 0: | |||||
| ke = self._edge_kernels['mix'] | |||||
| ek_temp = compute_ek_11 | |||||
| # edge symb labeled | |||||
| else: | |||||
| ke = self._edge_kernels['symb'] | |||||
| ek_temp = compute_ek_10 | |||||
| else: | |||||
| # edge non-synb labeled | |||||
| if len(self._edge_attrs) > 0: | |||||
| ke = self._edge_kernels['nsymb'] | |||||
| ek_temp = compute_ek_01 | |||||
| # edge unlabeled | |||||
| else: | |||||
| ke = None | |||||
| ek_temp = compute_ek_00 # @todo: check how much slower is this. | |||||
| # Compute the weight matrix. | |||||
| w_dim = nx.number_of_nodes(g1) * nx.number_of_nodes(g2) | |||||
| w_times = np.zeros((w_dim, w_dim)) | |||||
| if vk_dict: # node labeled | |||||
| if self._ds_infos['directed']: | |||||
| for e1 in g1.edges(data=True): | |||||
| for e2 in g2.edges(data=True): | |||||
| w_idx = (e1[0] * nx.number_of_nodes(g2) + e2[0], e1[1] * nx.number_of_nodes(g2) + e2[1]) | |||||
| w_times[w_idx] = vk_dict[(e1[0], e2[0])] * ek_temp(e1, e2, ke) * vk_dict[(e1[1], e2[1])] | |||||
| else: # undirected | |||||
| for e1 in g1.edges(data=True): | |||||
| for e2 in g2.edges(data=True): | |||||
| w_idx = (e1[0] * nx.number_of_nodes(g2) + e2[0], e1[1] * nx.number_of_nodes(g2) + e2[1]) | |||||
| w_times[w_idx] = vk_dict[(e1[0], e2[0])] * ek_temp(e1, e2, ke) * vk_dict[(e1[1], e2[1])] + vk_dict[(e1[0], e2[1])] * ek_temp(e1, e2, ke) * vk_dict[(e1[1], e2[0])] | |||||
| w_times[w_idx[1], w_idx[0]] = w_times[w_idx[0], w_idx[1]] | |||||
| w_idx2 = (e1[0] * nx.number_of_nodes(g2) + e2[1], e1[1] * nx.number_of_nodes(g2) + e2[0]) | |||||
| w_times[w_idx2[0], w_idx2[1]] = w_times[w_idx[0], w_idx[1]] | |||||
| w_times[w_idx2[1], w_idx2[0]] = w_times[w_idx[0], w_idx[1]] | |||||
| else: # node unlabeled | |||||
| if self._ds_infos['directed']: | |||||
| for e1 in g1.edges(data=True): | |||||
| for e2 in g2.edges(data=True): | |||||
| w_idx = (e1[0] * nx.number_of_nodes(g2) + e2[0], e1[1] * nx.number_of_nodes(g2) + e2[1]) | |||||
| w_times[w_idx] = ek_temp(e1, e2, ke) | |||||
| else: # undirected | |||||
| for e1 in g1.edges(data=True): | |||||
| for e2 in g2.edges(data=True): | |||||
| w_idx = (e1[0] * nx.number_of_nodes(g2) + e2[0], e1[1] * nx.number_of_nodes(g2) + e2[1]) | |||||
| w_times[w_idx] = ek_temp(e1, e2, ke) | |||||
| w_times[w_idx[1], w_idx[0]] = w_times[w_idx[0], w_idx[1]] | |||||
| w_idx2 = (e1[0] * nx.number_of_nodes(g2) + e2[1], e1[1] * nx.number_of_nodes(g2) + e2[0]) | |||||
| w_times[w_idx2[0], w_idx2[1]] = w_times[w_idx[0], w_idx[1]] | |||||
| w_times[w_idx2[1], w_idx2[0]] = w_times[w_idx[0], w_idx[1]] | |||||
| return w_times, w_dim | |||||