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| author | Thibaut Horel <thibaut.horel@gmail.com> | 2015-09-14 23:08:02 -0400 |
|---|---|---|
| committer | Thibaut Horel <thibaut.horel@gmail.com> | 2015-09-14 23:08:02 -0400 |
| commit | ab0b1f3cefedb35327a19ec1b6afd560bfdf802d (patch) | |
| tree | b777f3e2c0ac0e712d8c5faab5107b1d236e2c3a /ic_experiments/ml3.pyx | |
| parent | 960676226862d2d68c7a9c04c56d4f8157803025 (diff) | |
| download | criminal_cascades-ab0b1f3cefedb35327a19ec1b6afd560bfdf802d.tar.gz | |
Import supplements and repo reorganization
Diffstat (limited to 'ic_experiments/ml3.pyx')
| -rw-r--r-- | ic_experiments/ml3.pyx | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/ic_experiments/ml3.pyx b/ic_experiments/ml3.pyx new file mode 100644 index 0000000..6e031ef --- /dev/null +++ b/ic_experiments/ml3.pyx @@ -0,0 +1,91 @@ +# cython: boundscheck=False, cdivision=True +import numpy as np +cimport numpy as np +from libc.math cimport log, exp + +DTYPE = np.float64 +ctypedef np.float_t DTYPE_t + +cdef DTYPE_t weight_success(int dist, int dt, DTYPE_t alpha, DTYPE_t delta, + DTYPE_t w1, DTYPE_t w2, DTYPE_t w3): + """weight for successful infection, exponential time model""" + cdef DTYPE_t structural, temporal, result + structural = delta ** dist + temporal = log(exp(alpha)-1.) - alpha*dt + result = log(structural) + temporal + return result + +cdef DTYPE_t weight_failure(int dist, int dt, DTYPE_t alpha, DTYPE_t delta, + DTYPE_t w1, DTYPE_t w2, DTYPE_t w3): + """weight for failed infection, exponential time model""" + cdef DTYPE_t structural, temporal, result + structural = delta ** dist + temporal = exp(-alpha * dt) + result = log(1. - structural + structural * temporal) + return result + +def ml3(dict root_victims, dict victims, dict non_victims, DTYPE_t age, + DTYPE_t alpha, DTYPE_t delta): + cdef: + int n_roots, n_victims, roots, i, dist, dt, t, l + DTYPE_t beta, ll, beta_add, max_beta, max_beta_add + list parents, failures, successes + n_roots, n_victims = len(root_victims), len(victims) + cdef: + np.ndarray[DTYPE_t] probs = np.zeros(n_victims, dtype=DTYPE) + np.ndarray[DTYPE_t] probs_fail = np.zeros(n_victims, dtype=DTYPE) + np.ndarray[DTYPE_t] parent_dists = np.zeros(n_victims, dtype=DTYPE) + np.ndarray[DTYPE_t] parent_dts = np.zeros(n_victims, dtype=DTYPE) + + # loop through victims + for i, parents in enumerate(victims.itervalues()): + # for each victim node i, compute the probability that all its parents + # fail to infect it, also computes the probability that its most + # likely parent infects it + failures = [weight_failure(dist, dt, alpha, delta, w1, w2, w3) + for (prnt, dist, dt, w1, w2, w3) in parents] + probs_fail[i] = sum(failures) + successes = [weight_success(dist, dt, alpha, delta, w1, w2, w3) + for (prnt, dist, dt, w1, w2, w3) in parents] + dists = [dist for (prnt, dist, dt, w1, w2, w3) in parents] + dts = [dt for (prnt, dist, dt, w1, w2, w3) in parents] + # find parent that maximizes log(p) - log(\tilde{p}) + # probs[i] = max(s - failures[l] for l, s in enumerate(successes)) + probs[i] = float("-inf") + for l, s in enumerate(successes): + prob = s - failures[l] + if prob > probs[i]: + probs[i] = prob + parent_dists[i] = dists[l] + parent_dts[i] = dts[l] + # probs_fail[i] = failures[l] + + # calculate log likelihood + ll = probs_fail.sum() # add probability that all edges to all victims fail + + # print 'probs', probs + max_beta_add = float('-inf') + # iterate over all victim nodes to find the optimal threshold + for beta in np.arange(0.01, 1, .01): + thresh = log(beta/(3012.*(1.-beta))) + seeds = probs<thresh + non_seeds = probs>=thresh + roots = n_roots + sum(seeds) + + beta_add = 0. + # add probability for realized edges and subtract probability these edges fail + beta_add += (probs[non_seeds]).sum() + # add probability for the seeds and non-seeds + beta_add += roots * log(beta/3012.) + sum(non_seeds) * log(1. - beta) + + if beta_add > max_beta_add: + max_beta = beta + max_roots = roots + max_beta_add = beta_add + # print 'beta:', max_beta, 'add:', max_beta_add, 'roots:', max_roots + + ll += max_beta_add + roots = max_roots + beta = max_beta + # print n_nodes, n_roots, n_victims, max_i, roots + return (beta, roots, ll)
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