| @@ -0,0 +1,134 @@ | |||||
| #!/usr/bin/env python3 | |||||
| # -*- coding: utf-8 -*- | |||||
| """ | |||||
| compute gm with load_data.py and test them. | |||||
| Created on Wed Sep 19 16:12:13 2018 | |||||
| @author: ljia | |||||
| """ | |||||
| """Shortest-Path graph kernel. | |||||
| Python implementation based on: "Shortest-path kernels on graphs", by | |||||
| Borgwardt, K.M.; Kriegel, H.-P., in Data Mining, Fifth IEEE | |||||
| International Conference on , vol., no., pp.8 pp.-, 27-30 Nov. 2005 | |||||
| doi: 10.1109/ICDM.2005.132 | |||||
| Author : Sandro Vega-Pons, Emanuele Olivetti | |||||
| """ | |||||
| import sys | |||||
| sys.path.insert(0, "../../") | |||||
| import numpy as np | |||||
| import networkx as nx | |||||
| from gklearn.utils.graphfiles import loadDataset | |||||
| import matplotlib.pyplot as plt | |||||
| from numpy.linalg import eig | |||||
| class GK_SP: | |||||
| """ | |||||
| Shorthest path graph kernel. | |||||
| """ | |||||
| def compare(self, g_1, g_2, verbose=False): | |||||
| """Compute the kernel value (similarity) between two graphs. | |||||
| Parameters | |||||
| ---------- | |||||
| g1 : networkx.Graph | |||||
| First graph. | |||||
| g2 : networkx.Graph | |||||
| Second graph. | |||||
| Returns | |||||
| ------- | |||||
| k : The similarity value between g1 and g2. | |||||
| """ | |||||
| # Diagonal superior matrix of the floyd warshall shortest | |||||
| # paths: | |||||
| fwm1 = np.array(nx.floyd_warshall_numpy(g_1)) | |||||
| fwm1 = np.where(fwm1 == np.inf, 0, fwm1) | |||||
| fwm1 = np.where(fwm1 == np.nan, 0, fwm1) | |||||
| fwm1 = np.triu(fwm1, k=1) | |||||
| bc1 = np.bincount(fwm1.reshape(-1).astype(int)) | |||||
| fwm2 = np.array(nx.floyd_warshall_numpy(g_2)) | |||||
| fwm2 = np.where(fwm2 == np.inf, 0, fwm2) | |||||
| fwm2 = np.where(fwm2 == np.nan, 0, fwm2) | |||||
| fwm2 = np.triu(fwm2, k=1) | |||||
| bc2 = np.bincount(fwm2.reshape(-1).astype(int)) | |||||
| # Copy into arrays with the same length the non-zero shortests | |||||
| # paths: | |||||
| v1 = np.zeros(max(len(bc1), len(bc2)) - 1) | |||||
| v1[range(0, len(bc1)-1)] = bc1[1:] | |||||
| v2 = np.zeros(max(len(bc1), len(bc2)) - 1) | |||||
| v2[range(0, len(bc2)-1)] = bc2[1:] | |||||
| return np.sum(v1 * v2) | |||||
| def compare_normalized(self, g_1, g_2, verbose=False): | |||||
| """Compute the normalized kernel value between two graphs. | |||||
| A normalized version of the kernel is given by the equation: | |||||
| k_norm(g1, g2) = k(g1, g2) / sqrt(k(g1,g1) * k(g2,g2)) | |||||
| Parameters | |||||
| ---------- | |||||
| g1 : networkx.Graph | |||||
| First graph. | |||||
| g2 : networkx.Graph | |||||
| Second graph. | |||||
| Returns | |||||
| ------- | |||||
| k : The similarity value between g1 and g2. | |||||
| """ | |||||
| return self.compare(g_1, g_2) / (np.sqrt(self.compare(g_1, g_1) * | |||||
| self.compare(g_2, g_2))) | |||||
| def compare_list(self, graph_list, verbose=False): | |||||
| """Compute the all-pairs kernel values for a list of graphs. | |||||
| This function can be used to directly compute the kernel | |||||
| matrix for a list of graphs. The direct computation of the | |||||
| kernel matrix is faster than the computation of all individual | |||||
| pairwise kernel values. | |||||
| Parameters | |||||
| ---------- | |||||
| graph_list: list | |||||
| A list of graphs (list of networkx graphs) | |||||
| Return | |||||
| ------ | |||||
| K: numpy.array, shape = (len(graph_list), len(graph_list)) | |||||
| The similarity matrix of all graphs in graph_list. | |||||
| """ | |||||
| n = len(graph_list) | |||||
| k = np.zeros((n, n)) | |||||
| for i in range(n): | |||||
| for j in range(i, n): | |||||
| k[i, j] = self.compare(graph_list[i], graph_list[j]) | |||||
| k[j, i] = k[i, j] | |||||
| k_norm = np.zeros(k.shape) | |||||
| for i in range(k.shape[0]): | |||||
| for j in range(k.shape[1]): | |||||
| k_norm[i, j] = k[i, j] / np.sqrt(k[i, i] * k[j, j]) | |||||
| return k_norm | |||||
| ds_name = 'PAH' | |||||
| datafile = '../../datasets/PAH/dataset.ds' | |||||
| dataset, y = loadDataset(datafile, filename_y=None, extra_params=None) | |||||
| gk_sp = GK_SP() | |||||
| x = gk_sp.compare_list(dataset) | |||||
| np.savez('../check_gm/' + ds_name + '.gm.jstsp', gms=x) | |||||
| plt.imshow(x) | |||||
| plt.colorbar() | |||||
| plt.savefig('../check_gm/' + ds_name + '.gm.jstsp.eps', format='eps', dpi=300) | |||||
| # print(np.transpose(x)) | |||||
| print('if symmetric: ', np.array_equal(x, np.transpose(x))) | |||||
| print('diag: ', np.diag(x)) | |||||
| print('sum diag < 0.1: ', np.sum(np.diag(x) < 0.1)) | |||||
| print('min, max diag: ', min(np.diag(x)), max(np.diag(x))) | |||||
| print('mean x: ', np.mean(np.mean(x))) | |||||
| [lamnda, v] = eig(x) | |||||
| print('min, max lambda: ', min(lamnda), max(lamnda)) | |||||