#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ Created on Tue Apr 7 15:24:58 2020 @author: ljia @references: [1] Borgwardt KM, Kriegel HP. Shortest-path kernels on graphs. InData Mining, Fifth IEEE International Conference on 2005 Nov 27 (pp. 8-pp). IEEE. """ import sys from itertools import product # from functools import partial from multiprocessing import Pool from tqdm import tqdm import numpy as np from gklearn.utils.parallel import parallel_gm, parallel_me from gklearn.utils.utils import getSPGraph from gklearn.kernels import GraphKernel class ShortestPath(GraphKernel): def __init__(self, **kwargs): GraphKernel.__init__(self) self.__node_labels = kwargs.get('node_labels', []) self.__node_attrs = kwargs.get('node_attrs', []) self.__edge_weight = kwargs.get('edge_weight', None) self.__node_kernels = kwargs.get('node_kernels', None) self.__ds_infos = kwargs.get('ds_infos', {}) def _compute_gm_series(self): # get shortest path graph of each graph. if self._verbose >= 2: iterator = tqdm(self._graphs, desc='getting sp graphs', file=sys.stdout) else: iterator = self._graphs self._graphs = [getSPGraph(g, edge_weight=self.__edge_weight) for g in iterator] # compute Gram matrix. gram_matrix = np.zeros((len(self._graphs), len(self._graphs))) 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.__sp_do(self._graphs[i], self._graphs[j]) gram_matrix[i][j] = kernel gram_matrix[j][i] = kernel return gram_matrix def _compute_gm_imap_unordered(self): # get shortest path graph of each graph. pool = Pool(self._n_jobs) get_sp_graphs_fun = self._wrapper_get_sp_graphs itr = zip(self._graphs, range(0, len(self._graphs))) if len(self._graphs) < 100 * self._n_jobs: chunksize = int(len(self._graphs) / self._n_jobs) + 1 else: chunksize = 100 if self._verbose >= 2: iterator = tqdm(pool.imap_unordered(get_sp_graphs_fun, itr, chunksize), desc='getting sp graphs', file=sys.stdout) else: iterator = pool.imap_unordered(get_sp_graphs_fun, itr, chunksize) for i, g in iterator: self._graphs[i] = g pool.close() pool.join() # compute Gram matrix. gram_matrix = np.zeros((len(self._graphs), len(self._graphs))) def init_worker(gs_toshare): global G_gs G_gs = gs_toshare do_fun = self._wrapper_sp_do parallel_gm(do_fun, gram_matrix, self._graphs, init_worker=init_worker, glbv=(self._graphs,), n_jobs=self._n_jobs, verbose=self._verbose) return gram_matrix def _compute_kernel_list_series(self, g1, g_list): # get shortest path graphs of g1 and each graph in g_list. g1 = getSPGraph(g1, edge_weight=self.__edge_weight) if self._verbose >= 2: iterator = tqdm(g_list, desc='getting sp graphs', file=sys.stdout) else: iterator = g_list g_list = [getSPGraph(g, edge_weight=self.__edge_weight) for g in iterator] # compute kernel list. kernel_list = [None] * len(g_list) 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.__sp_do(g1, g_list[i]) kernel_list[i] = kernel return kernel_list def _compute_kernel_list_imap_unordered(self, g1, g_list): # get shortest path graphs of g1 and each graph in g_list. g1 = getSPGraph(g1, edge_weight=self.__edge_weight) pool = Pool(self._n_jobs) get_sp_graphs_fun = self._wrapper_get_sp_graphs itr = zip(g_list, range(0, len(g_list))) if len(g_list) < 100 * self._n_jobs: chunksize = int(len(g_list) / self._n_jobs) + 1 else: chunksize = 100 if self._verbose >= 2: iterator = tqdm(pool.imap_unordered(get_sp_graphs_fun, itr, chunksize), desc='getting sp graphs', file=sys.stdout) else: iterator = pool.imap_unordered(get_sp_graphs_fun, itr, chunksize) for i, g in iterator: g_list[i] = g pool.close() pool.join() # compute Gram matrix. kernel_list = [None] * len(g_list) def init_worker(g1_toshare, gl_toshare): global G_g1, G_gl G_g1 = g1_toshare G_gl = gl_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) return kernel_list def _wrapper_kernel_list_do(self, itr): return itr, self.__sp_do(G_g1, G_gl[itr]) def _compute_single_kernel_series(self, g1, g2): g1 = getSPGraph(g1, edge_weight=self.__edge_weight) g2 = getSPGraph(g2, edge_weight=self.__edge_weight) kernel = self.__sp_do(g1, g2) return kernel def _wrapper_get_sp_graphs(self, itr_item): g = itr_item[0] i = itr_item[1] return i, getSPGraph(g, edge_weight=self.__edge_weight) def __sp_do(self, g1, g2): kernel = 0 # compute shortest path matrices first, method borrowed from FCSP. vk_dict = {} # shortest path matrices dict if len(self.__node_labels) > 0: # node symb and non-synb labeled if len(self.__node_attrs) > 0: kn = self.__node_kernels['mix'] for n1, n2 in product( g1.nodes(data=True), g2.nodes(data=True)): n1_labels = [n1[1][nl] for nl in self.__node_labels] n2_labels = [n2[1][nl] for nl in self.__node_labels] n1_attrs = [n1[1][na] for na in self.__node_attrs] n2_attrs = [n2[1][na] for na in self.__node_attrs] vk_dict[(n1[0], n2[0])] = kn(n1_labels, n2_labels, n1_attrs, n2_attrs) # node symb labeled else: kn = self.__node_kernels['symb'] for n1 in g1.nodes(data=True): for n2 in g2.nodes(data=True): n1_labels = [n1[1][nl] for nl in self.__node_labels] n2_labels = [n2[1][nl] for nl in self.__node_labels] vk_dict[(n1[0], n2[0])] = kn(n1_labels, n2_labels) else: # node non-synb labeled if len(self.__node_attrs) > 0: kn = self.__node_kernels['nsymb'] for n1 in g1.nodes(data=True): for n2 in g2.nodes(data=True): n1_attrs = [n1[1][na] for na in self.__node_attrs] n2_attrs = [n2[1][na] for na in self.__node_attrs] vk_dict[(n1[0], n2[0])] = kn(n1_attrs, n2_attrs) # node unlabeled else: for e1, e2 in product( g1.edges(data=True), g2.edges(data=True)): if e1[2]['cost'] == e2[2]['cost']: kernel += 1 return kernel # compute graph kernels if self.__ds_infos['directed']: for e1, e2 in product(g1.edges(data=True), g2.edges(data=True)): if e1[2]['cost'] == e2[2]['cost']: nk11, nk22 = vk_dict[(e1[0], e2[0])], vk_dict[(e1[1], e2[1])] kn1 = nk11 * nk22 kernel += kn1 else: for e1, e2 in product(g1.edges(data=True), g2.edges(data=True)): if e1[2]['cost'] == e2[2]['cost']: # each edge walk is counted twice, starting from both its extreme nodes. nk11, nk12, nk21, nk22 = vk_dict[(e1[0], e2[0])], vk_dict[( e1[0], e2[1])], vk_dict[(e1[1], e2[0])], vk_dict[(e1[1], e2[1])] kn1 = nk11 * nk22 kn2 = nk12 * nk21 kernel += kn1 + kn2 # # ---- exact implementation of the Fast Computation of Shortest Path Kernel (FCSP), reference [2], sadly it is slower than the current implementation # # compute vertex kernels # try: # vk_mat = np.zeros((nx.number_of_nodes(g1), # nx.number_of_nodes(g2))) # g1nl = enumerate(g1.nodes(data=True)) # g2nl = enumerate(g2.nodes(data=True)) # for i1, n1 in g1nl: # for i2, n2 in g2nl: # vk_mat[i1][i2] = kn( # n1[1][node_label], n2[1][node_label], # [n1[1]['attributes']], [n2[1]['attributes']]) # range1 = range(0, len(edge_w_g[i])) # range2 = range(0, len(edge_w_g[j])) # for i1 in range1: # x1 = edge_x_g[i][i1] # y1 = edge_y_g[i][i1] # w1 = edge_w_g[i][i1] # for i2 in range2: # x2 = edge_x_g[j][i2] # y2 = edge_y_g[j][i2] # w2 = edge_w_g[j][i2] # ke = (w1 == w2) # if ke > 0: # kn1 = vk_mat[x1][x2] * vk_mat[y1][y2] # kn2 = vk_mat[x1][y2] * vk_mat[y1][x2] # kernel += kn1 + kn2 return kernel def _wrapper_sp_do(self, itr): i = itr[0] j = itr[1] return i, j, self.__sp_do(G_gs[i], G_gs[j])