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Diffstat (limited to 'jpa_test/cascade_creation.py')
| -rw-r--r-- | jpa_test/cascade_creation.py | 162 |
1 files changed, 0 insertions, 162 deletions
diff --git a/jpa_test/cascade_creation.py b/jpa_test/cascade_creation.py deleted file mode 100644 index 9a26c03..0000000 --- a/jpa_test/cascade_creation.py +++ /dev/null @@ -1,162 +0,0 @@ -import networkx as nx -import numpy as np -import collections -from itertools import izip -from sklearn.preprocessing import normalize - -class InfluenceGraph(nx.Graph): - """ - networkX graph with mat and logmat attributes - """ - def __init__(self, max_proba, *args, **kwargs): - self.max_proba = max_proba - super(InfluenceGraph, self).__init__(*args, **kwargs) - - def erdos_init(self, n, p): - G = nx.erdos_renyi_graph(n, p, directed=True) - self.add_edges_from(G.edges()) - - def import_from_file(self, file_name): - """ - Takes a file from the Stanford collection of networks - """ - with open(file_name, 'r') as f: - for edge in f: - if "#" not in edge: - u, v = [int(node) for node in edge.split()] - self.add_edge(u, v) - - @property - def mat(self): - if not hasattr(self, '_mat'): - self._mat = (self.max_proba * np.random.rand(len(self), len(self)) - * np.asarray(nx.adjacency_matrix(self))) - return self._mat - - @property - def logmat(self): - if not hasattr(self, '_logmat'): - self._logmat = np.log(1 - self.mat) - return self._logmat - - -class Cascade(list): - """ - Cascade object: list with attributes - """ - def __init__(self, *args, **kwargs): - super(Cascade, self).__init__(*args, **kwargs) - - def infection_time(self, node): - """ - Returns lists of infections times for node i in cascade - """ - infected_times = [] - for t, infected_set in izip(xrange(len(self)), self): - if infected_set[node]: - infected_times.append(t) - if not infected_times: - infected_times.append(None) - return infected_times - - def candidate_infectors(self, node): - """ - Returns Counter of nodes infected just before node i was - """ - candidate_infectors = collections.Counter() - for t in self.infection_time(node): - if t: # avoid cases where t=0 or t is None - candidate_infectors.update(np.where(self[t-1])[0]) - return candidate_infectors - - -def icc_cascade(G, p_init): - """ - Returns boolean vectors for one cascade - True means node was active at that time step - p_init: proba that node in seed set - """ - susceptible = np.ones(G.number_of_nodes(), dtype=bool) - active = np.random.rand(G.number_of_nodes()) < p_init - susceptible = susceptible & np.logical_not(active) - cascade = Cascade() - while active.any(): - cascade.append(active) - active = np.exp(np.dot(G.logmat, active)) \ - < np.random.rand(G.number_of_nodes()) - active = active & susceptible - susceptible = susceptible & np.logical_not(active) - if not cascade: - print "Empty cascade, consider changing p_init or n_nodes. Retrying." - return icc_cascade(G, p_init) - return cascade - - -def generate_cascades(G, p_init, n_cascades): - """ - returns list of cascades - """"" - return [icc_cascade(G,p_init) for i in xrange(n_cascades)] - - -def icc_matrixvector_for_node(cascades, node): - """ - for the ICC model: - Returns M, w in matrix form where rows of M are i = t + k.T - Excludes all (t,k) after node infection time; w = 1_{infected} - """ - #TODO: you need to remove the variable corresponding to the node - #you are solving for!!!! - if node is None: - return np.vstack(cascades), None - else: - w = [] - M = [] - for cascade in cascades: - t_i = cascade.infection_time(node)[0] - if t_i != 0: - indicator = np.zeros(len(cascade[:t_i])) - if t_i > 0: - indicator[-1] = 1 - w.append(indicator) - M.append(np.array(cascade[:t_i])) - M = np.vstack(M) - w = np.hstack(w) - return M, w - - -def normalize_matrix(M): - """ - returns M with normalized (L_1 norm) columns - """ - return normalize(M.astype("float32"), axis=0, norm="l2") - - -def add_edges_from_proba_vector(G, p_node, node, floor_cstt): - """ - Takes proba vector, node and adds edges to G by flooring very small - probabilities - Also updates G's mat matrix - """ - floor_parent = np.nonzero(p_node*(p_node > floor_cstt)) - for parent in floor_parent[0]: - G.add_edge(parent, node) - #TODO: update G's mat matrix - return G - - -def test(): - """ - unit test - """ - G = InfluenceGraph(max_proba = .3) - G.erdos_init(n = 10, p = 1) - import time - t0 = time.time() - A = generate_cascades(G, .1, 2) - M, w = icc_matrixvector_for_node(A, 0) - t1 = time.time() - print t1 - t0 - -if __name__ == "__main__": - test() |
