def fit_network_hawkes_gibbs(S, K, C, dt, dt_max,
output_path,
standard_model=None):
# Check for existing Gibbs results
if os.path.exists(output_path + ".gibbs.pkl"):
with open(output_path + ".gibbs.pkl", 'r') as f:
print "Loading Gibbs results from ", (output_path + ".gibbs.pkl")
(samples, timestamps) = cPickle.load(f)
else:
print "Fitting the data with a network Hawkes model using Gibbs sampling"
# Make a new model for inference
# test_model = DiscreteTimeNetworkHawkesModelGammaMixture(C=C, K=K, dt=dt, dt_max=dt_max, B=B,
# alpha=1.0, beta=1.0/20.0)
test_basis = IdentityBasis(dt, dt_max, allow_instantaneous=True)
network_hypers = {'C': C, 'alpha': 1.0, 'beta': 1.0/10.0,
'tau1': 1.0, 'tau0': 10.0,
'allow_self_connections': False}
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, dt_max=dt_max,
basis=test_basis,
network_hypers=network_hypers)
test_model.add_data(S)
# Initialize with the standard model parameters
if standard_model is not None:
test_model.initialize_with_standard_model(standard_model)
plt.ion()
im = plot_network(test_model.weight_model.A, test_model.weight_model.W, vmax=0.5)
plt.pause(0.001)
# Gibbs sample
N_samples = 100
samples = []
lps = [test_model.log_probability()]
timestamps = []
for itr in xrange(N_samples):
if itr % 1 == 0:
print "Iteration ", itr, "\tLL: ", lps[-1]
im.set_data(test_model.weight_model.W_effective)
plt.pause(0.001)
# lps.append(test_model.log_probability())
lps.append(test_model.log_probability())
samples.append(test_model.resample_and_copy())
timestamps.append(time.clock())
# Save this sample
with open(output_path + ".gibbs.itr%04d.pkl" % itr, 'w') as f:
cPickle.dump(samples[-1], f, protocol=-1)
# Save the Gibbs samples
with open(output_path + ".gibbs.pkl", 'w') as f:
print "Saving Gibbs samples to ", (output_path + ".gibbs.pkl")
cPickle.dump((samples, timestamps), f, protocol=-1)
return samples, timestamps
def demo(K=3, T=1000, dt_max=20, p=0.25):
"""
:param K: Number of nodes
:param T: Number of time bins to simulate
:param dt_max: Number of future time bins an event can influence
:param p: Sparsity of network
:return:
"""
###########################################################
# Generate synthetic data
###########################################################
network_hypers = {"p": p, "allow_self_connections": False}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max,
network_hypers=network_hypers)
assert true_model.check_stability()
# Sample from the true model
S,R = true_model.generate(T=T, keep=True, print_interval=50)
plt.ion()
true_figure, _ = true_model.plot(color="#377eb8", T_slice=(0,100))
###########################################################
# Create a test spike and slab model
###########################################################
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max,
network_hypers=network_hypers)
test_model.add_data(S)
# Initialize plots
test_figure, test_handles = test_model.plot(color="#e41a1c", T_slice=(0,100))
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 100
samples = []
lps = []
for itr in range(N_samples):
print("Gibbs iteration ", itr)
test_model.resample_model()
lps.append(test_model.log_probability())
samples.append(test_model.copy_sample())
# Update plots
test_model.plot(handles=test_handles)
###########################################################
# Analyze the samples
###########################################################
analyze_samples(true_model, samples, lps)
def demo(K=3, T=1000, dt_max=20, p=0.25):
"""
:param K: Number of nodes
:param T: Number of time bins to simulate
:param dt_max: Number of future time bins an event can influence
:param p: Sparsity of network
:return:
"""
###########################################################
# Generate synthetic data
###########################################################
network_hypers = {"p": p, "allow_self_connections": False}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max,
network_hypers=network_hypers)
assert true_model.check_stability()
# Sample from the true model
S,R = true_model.generate(T=T, keep=True, print_interval=50)
plt.ion()
true_figure, _ = true_model.plot(color="#377eb8", T_slice=(0,100))
###########################################################
# Create a test spike and slab model
###########################################################
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max,
network_hypers=network_hypers)
test_model.add_data(S)
# Initialize plots
test_figure, test_handles = test_model.plot(color="#e41a1c", T_slice=(0,100))
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 100
samples = []
lps = []
for itr in xrange(N_samples):
print "Gibbs iteration ", itr
test_model.resample_model()
lps.append(test_model.log_probability())
samples.append(test_model.copy_sample())
# Update plots
test_model.plot(handles=test_handles)
###########################################################
# Analyze the samples
###########################################################
analyze_samples(true_model, samples, lps)
def fit_network_hawkes_gibbs_ss(S, K, C, B, dt, dt_max,
output_path, p,
standard_model=None):
samples_and_timestamps = load_partial_results(output_path, typ="gibbs_ss")
if samples_and_timestamps is not None:
samples, timestamps = samples_and_timestamps
else:
print "Fitting the data with a spike and slab network Hawkes model using Gibbs sampling"
# Make a new model for inference
network_hypers = {'C': C, 'alpha': 1.0, 'beta': 1.0/20.0, 'p': p,
'v': 5.0,'c': np.arange(C).repeat((K // C))}
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, dt_max=dt_max, B=B,
network_hypers=network_hypers)
test_model.add_data(S)
# Initialize with the standard model parameters
if standard_model is not None:
test_model.initialize_with_standard_model(standard_model)
# Gibbs sample
N_samples = 1000
samples = []
lps = []
timestamps = [time.clock()]
for itr in xrange(N_samples):
lps.append(test_model.log_probability())
samples.append(test_model.resample_and_copy())
timestamps.append(time.clock())
print test_model.network.v
if itr % 1 == 0:
print "Iteration ", itr, "\t LP: ", lps[-1]
# Save this sample
with open(output_path + ".gibbs_ss.itr%04d.pkl" % itr, 'w') as f:
cPickle.dump((samples[-1], timestamps[-1]-timestamps[0]), f, protocol=-1)
# Save the Gibbs timestamps
timestamps = np.array(timestamps)
with open(output_path + ".gibbs_ss.timestamps.pkl", 'w') as f:
print "Saving spike and slab Gibbs samples to ", (output_path + ".gibbs_ss.timestamps.pkl")
cPickle.dump(timestamps, f, protocol=-1)
# Save the Gibbs samples
with open(output_path + ".gibbs_ss.pkl", 'w') as f:
print "Saving Gibbs samples to ", (output_path + ".gibbs_ss.pkl")
cPickle.dump((samples, timestamps[1:] - timestamps[0]), f, protocol=-1)
return samples, timestamps
def demo(K=3, T=1000, dt_max=20, p=0.25):
"""
:param K: Number of nodes
:param T: Number of time bins to simulate
:param dt_max: Number of future time bins an event can influence
:param p: Sparsity of network
:return:
"""
###########################################################
# Generate synthetic data
###########################################################
network = ErdosRenyiFixedSparsity(K, p, v=1., allow_self_connections=False)
bkgd_hypers = {"alpha": 1.0, "beta": 20.0}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max, bkgd_hypers=bkgd_hypers, network=network)
A_true = np.zeros((K, K))
A_true[0, 1] = A_true[0, 2] = 1
W_true = np.zeros((K, K))
W_true[0, 1] = W_true[0, 2] = 1.0
true_model.weight_model.A = A_true
true_model.weight_model.W = W_true
true_model.bias_model.lambda0[0] = 0.2
assert true_model.check_stability()
# Sample from the true model
S, R = true_model.generate(T=T, keep=True, print_interval=50)
plt.ion()
true_figure, _ = true_model.plot(color="#377eb8", T_slice=(0, 100))
# Save the true figure
true_figure.savefig("gifs/true.gif")
###########################################################
# Create a test spike and slab model
###########################################################
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K,
dt_max=dt_max,
network=network)
test_model.add_data(S)
# Initialize plots
test_figure, test_handles = test_model.plot(color="#e41a1c",
T_slice=(0, 100))
test_figure.savefig("gifs/test0.gif")
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 100
samples = []
lps = []
for itr in xrange(N_samples):
print "Gibbs iteration ", itr
test_model.resample_model()
lps.append(test_model.log_probability())
samples.append(test_model.copy_sample())
# Update plots
test_model.plot(handles=test_handles)
test_figure.savefig("gifs/test%d.gif" % (itr + 1))
def test_gibbs_sbm(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print "Setting seed to ", seed
np.random.seed(seed)
C = 10
K = 100
T = 1000
dt = 1.0
B = 3
# Generate from a true model
network_hypers = {'C': C, 'beta': 1.0 / K}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network_hypers=network_hypers)
# S,R = true_model.generate(T=T)
c = true_model.network.c
perm = np.argsort(c)
# Plot the true network
plt.ion()
plot_network(true_model.weight_model.A[np.ix_(perm, perm)],
true_model.weight_model.W[np.ix_(perm, perm)])
plt.pause(0.001)
# Make a new model for inference
network_hypers = {'C': C, 'beta': 1.0 / K}
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network_hypers=network_hypers)
# test_model.add_data(S)
# Gibbs sample
N_samples = 10
samples = []
lps = []
for itr in xrange(N_samples):
if itr % 5 == 0:
print "Iteration: ", itr
samples.append(copy.deepcopy(test_model.get_parameters()))
lps.append(test_model.log_probability())
# Resample the network only
test_model.network.resample(
(true_model.weight_model.A, true_model.weight_model.W))
plt.ioff()
# Compute sample statistics for second half of samples
c_samples = np.array([c for _, _, _, _, c, _, _, _ in samples])
print "True c: ", true_model.network.c
print "Test c: ", c_samples[-10:, :]
# Compute the adjusted mutual info score of the clusterings
amis = []
arss = []
for c in c_samples:
amis.append(adjusted_mutual_info_score(true_model.network.c, c))
arss.append(adjusted_rand_score(true_model.network.c, c))
plt.figure()
plt.plot(np.arange(N_samples), amis, '-r')
plt.plot(np.arange(N_samples), arss, '-b')
plt.xlabel("Iteration")
plt.ylabel("Clustering score")
plt.show()
def fit_spikeslab_network_hawkes_gibbs(S,
S_test,
dt,
dt_max,
output_path,
model_args={},
standard_model=None,
N_samples=100,
time_limit=8 * 60 * 60):
T, K = S.shape
# Check for existing Gibbs results
if os.path.exists(output_path):
with gzip.open(output_path, 'r') as f:
print("Loading Gibbs results from ", output_path)
results = pickle.load(f)
else:
print(
"Fitting the data with a network Hawkes model using Gibbs sampling"
)
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K,
dt=dt,
dt_max=dt_max,
**model_args)
test_model.add_data(S)
# Initialize with the standard model parameters
if standard_model is not None:
test_model.initialize_with_standard_model(standard_model)
# TODO: Precompute F_test
F_test = test_model.basis.convolve_with_basis(S_test)
# Gibbs sample
samples = []
lps = [test_model.log_probability()]
hlls = [test_model.heldout_log_likelihood(S_test)]
times = [0]
for _ in progprint_xrange(N_samples, perline=10):
# Update the model
tic = time.time()
test_model.resample_model()
samples.append(copy.deepcopy(test_model.get_parameters()))
times.append(time.time() - tic)
# Compute log probability and heldout log likelihood
# lps.append(test_model.log_probability())
hlls.append(test_model.heldout_log_likelihood(S_test, F=F_test))
# # Save this sample
# with open(output_path + ".gibbs.itr%04d.pkl" % itr, 'w') as f:
# cPickle.dump(samples[-1], f, protocol=-1)
# Check if time limit has been exceeded
if np.sum(times) > time_limit:
break
# Get cumulative timestamps
timestamps = np.cumsum(times)
lps = np.array(lps)
hlls = np.array(hlls)
# Make results object
results = Results(samples, timestamps, lps, hlls)
# Save the Gibbs samples
with gzip.open(output_path, 'w') as f:
print("Saving Gibbs samples to ", output_path)
pickle.dump(results, f, protocol=-1)
return results
def demo(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print("Setting seed to ", seed)
np.random.seed(seed)
###########################################################
# Load some example data.
# See data/synthetic/generate.py to create more.
###########################################################
data_path = os.path.join("data", "synthetic",
"synthetic_K20_C4_T10000.pkl.gz")
with gzip.open(data_path, 'r') as f:
S, true_model = pickle.load(f)
T = S.shape[0]
K = true_model.K
B = true_model.B
dt = true_model.dt
dt_max = true_model.dt_max
###########################################################
# Initialize with MAP estimation on a standard Hawkes model
###########################################################
init_with_map = True
if init_with_map:
init_len = T
print("Initializing with BFGS on first ", init_len, " time bins.")
init_model = DiscreteTimeStandardHawkesModel(K=K,
dt=dt,
dt_max=dt_max,
B=B,
alpha=1.0,
beta=1.0)
init_model.add_data(S[:init_len, :])
init_model.initialize_to_background_rate()
init_model.fit_with_bfgs()
else:
init_model = None
###########################################################
# Create a test spike and slab model
###########################################################
# Copy the network hypers.
# Give the test model p, but not c, v, or m
network_hypers = true_model.network_hypers.copy()
network_hypers['c'] = None
network_hypers['v'] = None
network_hypers['m'] = None
test_network = StochasticBlockModel(K=K, **network_hypers)
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K,
dt=dt,
dt_max=dt_max,
B=B,
basis_hypers=true_model.basis_hypers,
bkgd_hypers=true_model.bkgd_hypers,
impulse_hypers=true_model.impulse_hypers,
weight_hypers=true_model.weight_hypers,
network=test_network)
test_model.add_data(S)
# F_test = test_model.basis.convolve_with_basis(S_test)
# Initialize with the standard model parameters
if init_model is not None:
test_model.initialize_with_standard_model(init_model)
# Initialize plots
ln, im_net, im_clus = initialize_plots(true_model, test_model, S)
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 50
samples = []
lps = []
# plls = []
for itr in range(N_samples):
lps.append(test_model.log_probability())
# plls.append(test_model.heldout_log_likelihood(S_test, F=F_test))
samples.append(test_model.copy_sample())
print("")
print("Gibbs iteration ", itr)
print("LP: ", lps[-1])
test_model.resample_model()
# Update plot
if itr % 1 == 0:
update_plots(itr, test_model, S, ln, im_clus, im_net)
###########################################################
# Analyze the samples
###########################################################
analyze_samples(true_model, init_model, samples, lps)
def geweke_test():
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
T = 50
dt = 1.0
dt_max = 3.0
network_hypers = {
'C': 1,
'p': 0.5,
'kappa': 3.0,
'alpha': 3.0,
'beta': 1.0 / 20.0
}
model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=1, dt=dt, dt_max=dt_max, network_hypers=network_hypers)
model.generate(T=T)
# Gibbs sample and then generate new data
N_samples = 10000
samples = []
lps = []
for itr in xrange(N_samples):
if itr % 10 == 0:
print "Iteration: ", itr
# Resample the model
model.resample_model()
samples.append(model.copy_sample())
lps.append(model.log_probability())
# Geweke step
model.data_list.pop()
model.generate(T=T)
# Compute sample statistics for second half of samples
A_samples = np.array([s.weight_model.A for s in samples])
W_samples = np.array([s.weight_model.W for s in samples])
g_samples = np.array([s.impulse_model.g for s in samples])
lambda0_samples = np.array([s.bias_model.lambda0 for s in samples])
c_samples = np.array([s.network.c for s in samples])
p_samples = np.array([s.network.p for s in samples])
v_samples = np.array([s.network.v for s in samples])
lps = np.array(lps)
offset = 0
A_mean = A_samples[offset:, ...].mean(axis=0)
W_mean = W_samples[offset:, ...].mean(axis=0)
g_mean = g_samples[offset:, ...].mean(axis=0)
lambda0_mean = lambda0_samples[offset:, ...].mean(axis=0)
print "A mean: ", A_mean
print "W mean: ", W_mean
print "g mean: ", g_mean
print "lambda0 mean: ", lambda0_mean
# Plot the log probability over iterations
plt.figure()
plt.plot(np.arange(N_samples), lps)
plt.xlabel("Iteration")
plt.ylabel("Log probability")
# Plot the histogram of bias samples
plt.figure()
p_lmbda0 = gamma(model.bias_model.alpha, scale=1. / model.bias_model.beta)
_, bins, _ = plt.hist(lambda0_samples[:, 0],
bins=20,
alpha=0.5,
normed=True)
bincenters = 0.5 * (bins[1:] + bins[:-1])
plt.plot(bincenters, p_lmbda0.pdf(bincenters), 'r--', linewidth=1)
plt.xlabel('lam0')
plt.ylabel('p(lam0)')
print "Expected p(A): ", model.network.P
print "Empirical p(A): ", A_samples.mean(axis=0)
# Plot the histogram of weight samples
plt.figure()
Aeq1 = A_samples[:, 0, 0] == 1
# p_W1 = gamma(model.network.kappa, scale=1./model.network.v[0,0])
# The marginal distribution of W under a gamma prior on the scale
# is a beta prime distribution
p_W1 = betaprime(model.network.kappa,
model.network.alpha,
scale=model.network.beta)
_, bins, _ = plt.hist(W_samples[Aeq1, 0, 0],
bins=20,
alpha=0.5,
normed=True)
bincenters = 0.5 * (bins[1:] + bins[:-1])
plt.plot(bincenters, p_W1.pdf(bincenters), 'r--', linewidth=1)
plt.xlabel('W')
plt.ylabel('p(W | A=1)')
# Plot the histogram of impulse samples
plt.figure()
for b in range(model.B):
plt.subplot(1, model.B, b + 1)
a = model.impulse_model.gamma[b]
b = model.impulse_model.gamma.sum() - a
p_beta11b = beta(a, b)
_, bins, _ = plt.hist(g_samples[:, 0, 0, b],
bins=20,
alpha=0.5,
normed=True)
bincenters = 0.5 * (bins[1:] + bins[:-1])
plt.plot(bincenters, p_beta11b.pdf(bincenters), 'r--', linewidth=1)
plt.xlabel('g_%d' % b)
plt.ylabel('p(g_%d)' % b)
# Plot the histogram of weight scale
plt.figure()
for c1 in range(model.C):
for c2 in range(model.C):
plt.subplot(model.C, model.C, 1 + c1 * model.C + c2)
p_v = gamma(model.network.alpha, scale=1. / model.network.beta)
_, bins, _ = plt.hist(v_samples[:, c1, c2],
bins=20,
alpha=0.5,
normed=True)
bincenters = 0.5 * (bins[1:] + bins[:-1])
plt.plot(bincenters, p_v.pdf(bincenters), 'r--', linewidth=1)
plt.xlabel('v_{%d,%d}' % (c1, c2))
plt.ylabel('p(v)')
plt.show()
def fit_network_hawkes_gibbs(S, K, C, dt, dt_max, output_path, standard_model=None):
# Check for existing Gibbs results
if os.path.exists(output_path + ".gibbs.pkl"):
with open(output_path + ".gibbs.pkl", "r") as f:
print "Loading Gibbs results from ", (output_path + ".gibbs.pkl")
(samples, timestamps) = cPickle.load(f)
else:
print "Fitting the data with a network Hawkes model using Gibbs sampling"
# Make a new model for inference
# test_model = DiscreteTimeNetworkHawkesModelGammaMixture(C=C, K=K, dt=dt, dt_max=dt_max, B=B,
# alpha=1.0, beta=1.0/20.0)
test_basis = IdentityBasis(dt, dt_max, allow_instantaneous=True)
# Set the network prior such that E[W] ~= 0.01
# W ~ Gamma(kappa, v) for kappa = 1.25 => v ~ 125
# v ~ Gamma(alpha, beta) for alpha = 10, beta = 10 / 125
E_W = 0.01
kappa = 10.0
E_v = kappa / E_W
alpha = 10.0
beta = alpha / E_v
network_hypers = {
"C": 2,
"kappa": kappa,
"alpha": alpha,
"beta": beta,
"p": 0.8,
"allow_self_connections": False,
}
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, dt_max=dt_max, basis=test_basis, network_hypers=network_hypers
)
test_model.add_data(S)
# Initialize with the standard model parameters
if standard_model is not None:
test_model.initialize_with_standard_model(standard_model)
plt.ion()
im = plot_network(test_model.weight_model.A, test_model.weight_model.W, vmax=0.5)
plt.pause(0.001)
# Gibbs sample
N_samples = 100
samples = []
lps = [test_model.log_probability()]
timestamps = []
for itr in xrange(N_samples):
if itr % 1 == 0:
print "Iteration ", itr, "\tLL: ", lps[-1]
im.set_data(test_model.weight_model.W_effective)
plt.pause(0.001)
# lps.append(test_model.log_probability())
lps.append(test_model.log_probability())
samples.append(test_model.resample_and_copy())
timestamps.append(time.clock())
# Save this sample
with open(output_path + ".gibbs.itr%04d.pkl" % itr, "w") as f:
cPickle.dump(samples[-1], f, protocol=-1)
# Save the Gibbs samples
with open(output_path + ".gibbs.pkl", "w") as f:
print "Saving Gibbs samples to ", (output_path + ".gibbs.pkl")
cPickle.dump((samples, timestamps), f, protocol=-1)
return samples, timestamps
def fit_spikeslab_network_hawkes_gibbs(S, S_test, dt, dt_max, output_path,
model_args={}, standard_model=None,
N_samples=100, time_limit=8*60*60):
T,K = S.shape
# Check for existing Gibbs results
if os.path.exists(output_path):
with gzip.open(output_path, 'r') as f:
print "Loading Gibbs results from ", output_path
results = cPickle.load(f)
else:
print "Fitting the data with a network Hawkes model using Gibbs sampling"
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, dt_max=dt_max, **model_args)
test_model.add_data(S)
# Initialize with the standard model parameters
if standard_model is not None:
test_model.initialize_with_standard_model(standard_model)
# TODO: Precompute F_test
F_test = test_model.basis.convolve_with_basis(S_test)
# Gibbs sample
samples = []
lps = [test_model.log_probability()]
hlls = [test_model.heldout_log_likelihood(S_test)]
times = [0]
for _ in progprint_xrange(N_samples, perline=10):
# Update the model
tic = time.time()
test_model.resample_model()
samples.append(copy.deepcopy(test_model.get_parameters()))
times.append(time.time() - tic)
# Compute log probability and heldout log likelihood
# lps.append(test_model.log_probability())
hlls.append(test_model.heldout_log_likelihood(S_test, F=F_test))
# # Save this sample
# with open(output_path + ".gibbs.itr%04d.pkl" % itr, 'w') as f:
# cPickle.dump(samples[-1], f, protocol=-1)
# Check if time limit has been exceeded
if np.sum(times) > time_limit:
break
# Get cumulative timestamps
timestamps = np.cumsum(times)
lps = np.array(lps)
hlls = np.array(hlls)
# Make results object
results = Results(samples, timestamps, lps, hlls)
# Save the Gibbs samples
with gzip.open(output_path, 'w') as f:
print "Saving Gibbs samples to ", output_path
cPickle.dump(results, f, protocol=-1)
return results
def demo(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print "Setting seed to ", seed
np.random.seed(seed)
###########################################################
# Load some example data.
# See data/synthetic/generate.py to create more.
###########################################################
data_path = os.path.join("data", "synthetic", "synthetic_K20_C4_T10000.pkl.gz")
with gzip.open(data_path, 'r') as f:
S, true_model = cPickle.load(f)
T = S.shape[0]
K = true_model.K
B = true_model.B
dt = true_model.dt
dt_max = true_model.dt_max
###########################################################
# Initialize with MAP estimation on a standard Hawkes model
###########################################################
init_with_map = True
if init_with_map:
init_len = T
print "Initializing with BFGS on first ", init_len, " time bins."
init_model = DiscreteTimeStandardHawkesModel(K=K, dt=dt, dt_max=dt_max, B=B,
alpha=1.0, beta=1.0)
init_model.add_data(S[:init_len, :])
init_model.initialize_to_background_rate()
init_model.fit_with_bfgs()
else:
init_model = None
###########################################################
# Create a test spike and slab model
###########################################################
# Copy the network hypers.
# Give the test model p, but not c, v, or m
network_hypers = true_model.network_hypers.copy()
network_hypers['c'] = None
network_hypers['v'] = None
network_hypers['m'] = None
test_network = StochasticBlockModel(K=K, **network_hypers)
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, dt_max=dt_max, B=B,
basis_hypers=true_model.basis_hypers,
bkgd_hypers=true_model.bkgd_hypers,
impulse_hypers=true_model.impulse_hypers,
weight_hypers=true_model.weight_hypers,
network=test_network)
test_model.add_data(S)
# F_test = test_model.basis.convolve_with_basis(S_test)
# Initialize with the standard model parameters
if init_model is not None:
test_model.initialize_with_standard_model(init_model)
# Initialize plots
ln, im_net, im_clus = initialize_plots(true_model, test_model, S)
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 50
samples = []
lps = []
# plls = []
for itr in xrange(N_samples):
lps.append(test_model.log_probability())
# plls.append(test_model.heldout_log_likelihood(S_test, F=F_test))
samples.append(test_model.copy_sample())
print ""
print "Gibbs iteration ", itr
print "LP: ", lps[-1]
test_model.resample_model()
# Update plot
if itr % 1 == 0:
update_plots(itr, test_model, S, ln, im_clus, im_net)
###########################################################
# Analyze the samples
###########################################################
analyze_samples(true_model, init_model, samples, lps)
def test_gibbs_sbm(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print("Setting seed to ", seed)
np.random.seed(seed)
C = 2
K = 100
c = np.arange(C).repeat(np.ceil(K/float(C)))[:K]
T = 1000
dt = 1.0
B = 3
# Generate from a true model
true_p = np.random.rand(C,C) * 0.25
true_network = StochasticBlockModel(K, C, c=c, p=true_p, v=10.0)
true_model = \
DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network=true_network)
S,R = true_model.generate(T)
# Plot the true network
plt.ion()
true_im = true_model.plot_adjacency_matrix()
plt.pause(0.001)
# Make a new model for inference
test_network = StochasticBlockModel(K, C, beta=1./K)
test_model = \
DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network=test_network)
test_model.add_data(S)
# Gibbs sample
N_samples = 100
c_samples = []
lps = []
for itr in progprint_xrange(N_samples):
c_samples.append(test_network.c.copy())
lps.append(test_model.log_probability())
# Resample the network only
test_model.network.resample((true_model.weight_model.A,
true_model.weight_model.W))
c_samples = np.array(c_samples)
plt.ioff()
# Compute sample statistics for second half of samples
print("True c: ", true_model.network.c)
print("Test c: ", c_samples[-10:, :])
# Compute the adjusted mutual info score of the clusterings
amis = []
arss = []
for c in c_samples:
amis.append(adjusted_mutual_info_score(true_model.network.c, c))
arss.append(adjusted_rand_score(true_model.network.c, c))
plt.figure()
plt.plot(np.arange(N_samples), amis, '-r')
plt.plot(np.arange(N_samples), arss, '-b')
plt.xlabel("Iteration")
plt.ylabel("Clustering score")
plt.show()
def test_gibbs_sbm(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print("Setting seed to ", seed)
np.random.seed(seed)
C = 2
K = 100
c = np.arange(C).repeat(np.ceil(K / float(C)))[:K]
T = 1000
dt = 1.0
B = 3
# Generate from a true model
true_p = np.random.rand(C, C) * 0.25
true_network = StochasticBlockModel(K, C, c=c, p=true_p, v=10.0)
true_model = \
DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network=true_network)
S, R = true_model.generate(T)
# Plot the true network
plt.ion()
true_im = true_model.plot_adjacency_matrix()
plt.pause(0.001)
# Make a new model for inference
test_network = StochasticBlockModel(K, C, beta=1. / K)
test_model = \
DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt=dt, B=B, network=test_network)
test_model.add_data(S)
# Gibbs sample
N_samples = 100
c_samples = []
lps = []
for itr in progprint_xrange(N_samples):
c_samples.append(test_network.c.copy())
lps.append(test_model.log_probability())
# Resample the network only
test_model.network.resample(
(true_model.weight_model.A, true_model.weight_model.W))
c_samples = np.array(c_samples)
plt.ioff()
# Compute sample statistics for second half of samples
print("True c: ", true_model.network.c)
print("Test c: ", c_samples[-10:, :])
# Compute the adjusted mutual info score of the clusterings
amis = []
arss = []
for c in c_samples:
amis.append(adjusted_mutual_info_score(true_model.network.c, c))
arss.append(adjusted_rand_score(true_model.network.c, c))
plt.figure()
plt.plot(np.arange(N_samples), amis, '-r')
plt.plot(np.arange(N_samples), arss, '-b')
plt.xlabel("Iteration")
plt.ylabel("Clustering score")
plt.show()
def demo(K=3, T=1000, dt_max=20, p=0.25):
"""
:param K: Number of nodes
:param T: Number of time bins to simulate
:param dt_max: Number of future time bins an event can influence
:param p: Sparsity of network
:return:
"""
###########################################################
# Generate synthetic data
###########################################################
network = ErdosRenyiFixedSparsity(K, p, v=1., allow_self_connections=False)
bkgd_hypers = {"alpha": 1.0, "beta": 20.0}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max, bkgd_hypers=bkgd_hypers, network=network)
A_true = np.zeros((K,K))
A_true[0,1] = A_true[0,2] = 1
W_true = np.zeros((K,K))
W_true[0,1] = W_true[0,2] = 1.0
true_model.weight_model.A = A_true
true_model.weight_model.W = W_true
true_model.bias_model.lambda0[0] = 0.2
assert true_model.check_stability()
# Sample from the true model
S,R = true_model.generate(T=T, keep=True, print_interval=50)
plt.ion()
true_figure, _ = true_model.plot(color="#377eb8", T_slice=(0,100))
# Save the true figure
true_figure.savefig("gifs/true.gif")
###########################################################
# Create a test spike and slab model
###########################################################
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(
K=K, dt_max=dt_max, network=network)
test_model.add_data(S)
# Initialize plots
test_figure, test_handles = test_model.plot(color="#e41a1c", T_slice=(0,100))
test_figure.savefig("gifs/test0.gif")
###########################################################
# Fit the test model with Gibbs sampling
###########################################################
N_samples = 100
samples = []
lps = []
for itr in xrange(N_samples):
print "Gibbs iteration ", itr
test_model.resample_model()
lps.append(test_model.log_probability())
samples.append(test_model.copy_sample())
# Update plots
test_model.plot(handles=test_handles)
test_figure.savefig("gifs/test%d.gif" % (itr+1))
def test_gibbs_sbm(seed=None):
"""
Create a discrete time Hawkes model and generate from it.
:return:
"""
if seed is None:
seed = np.random.randint(2**32)
print "Setting seed to ", seed
np.random.seed(seed)
C = 10
K = 100
T = 1000
dt = 1.0
B = 3
# Generate from a true model
network_hypers = {'C': C, 'beta': 1.0/K}
true_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, B=B,
network_hypers=network_hypers)
# S,R = true_model.generate(T=T)
c = true_model.network.c
perm = np.argsort(c)
# Plot the true network
plt.ion()
plot_network(true_model.weight_model.A[np.ix_(perm, perm)],
true_model.weight_model.W[np.ix_(perm, perm)])
plt.pause(0.001)
# Make a new model for inference
network_hypers = {'C': C, 'beta': 1.0/K}
test_model = DiscreteTimeNetworkHawkesModelSpikeAndSlab(K=K, dt=dt, B=B,
network_hypers=network_hypers)
# test_model.add_data(S)
# Gibbs sample
N_samples = 10
samples = []
lps = []
for itr in xrange(N_samples):
if itr % 5 == 0:
print "Iteration: ", itr
samples.append(copy.deepcopy(test_model.get_parameters()))
lps.append(test_model.log_probability())
# Resample the network only
test_model.network.resample((true_model.weight_model.A,
true_model.weight_model.W))
plt.ioff()
# Compute sample statistics for second half of samples
c_samples = np.array([c for _,_,_,_,c,_,_,_ in samples])
print "True c: ", true_model.network.c
print "Test c: ", c_samples[-10:, :]
# Compute the adjusted mutual info score of the clusterings
amis = []
arss = []
for c in c_samples:
amis.append(adjusted_mutual_info_score(true_model.network.c, c))
arss.append(adjusted_rand_score(true_model.network.c, c))
plt.figure()
plt.plot(np.arange(N_samples), amis, '-r')
plt.plot(np.arange(N_samples), arss, '-b')
plt.xlabel("Iteration")
plt.ylabel("Clustering score")
plt.show()
