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| #!/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 | |||