def test_simu_hawkes_multi_time_func(self):
"""...Test that hawkes multi works correctly with HawkesKernelTimeFunc
"""
run_time = 100
t_values1 = np.array([0, 1, 1.5], dtype=float)
y_values1 = np.array([0, .2, 0], dtype=float)
tf1 = TimeFunction([t_values1, y_values1],
inter_mode=TimeFunction.InterConstRight, dt=0.1)
kernel1 = HawkesKernelTimeFunc(tf1)
t_values2 = np.array([0, 2, 2.5], dtype=float)
y_values2 = np.array([0, .6, 0], dtype=float)
tf2 = TimeFunction([t_values2, y_values2],
inter_mode=TimeFunction.InterConstRight, dt=0.1)
kernel2 = HawkesKernelTimeFunc(tf2)
baseline = np.array([0.1, 0.3])
hawkes = SimuHawkes(baseline=baseline, end_time=run_time,
verbose=False, seed=2334)
hawkes.set_kernel(0, 0, kernel1)
hawkes.set_kernel(0, 1, kernel1)
hawkes.set_kernel(1, 0, kernel2)
hawkes.set_kernel(1, 1, kernel2)
hawkes_multi = SimuHawkesMulti(hawkes, n_simulations=5, n_threads=4)
hawkes_multi.simulate()
def test_hawkes_set_kernel(self):
"""...Test Hawkes process kernels can be set after initialization
"""
hawkes = SimuHawkes(n_nodes=2)
for i, j in product(range(2), range(2)):
hawkes.set_kernel(i, j, self.kernels[i, j])
for i, j in product(range(2), range(2)):
self.assertEqual(hawkes.kernels[i, j], self.kernels[i, j])
hawkes.set_kernel(1, 1, self.time_func_kernel)
self.assertEqual(hawkes.kernels[1, 1], self.time_func_kernel)
def test_hawkes_negative_intensity_fail(self):
"""...Test simulation with negative kernel without threshold_negative_intensity
"""
run_time = 40
hawkes = SimuHawkes(n_nodes=1,
end_time=run_time,
verbose=False,
seed=1398)
kernel = HawkesKernelExp(-1.3, .8)
hawkes.set_kernel(0, 0, kernel)
hawkes.set_baseline(0, 0.3)
msg = 'Simulation stopped because intensity went negative ' \
'\(you could call ``threshold_negative_intensity`` to allow it\)'
with self.assertRaisesRegex(RuntimeError, msg):
hawkes.simulate()
def test_simu_hawkes_no_seed(self):
"""...Test hawkes multi can be simulated even if no seed is given
"""
T1 = np.array([0, 2, 2.5], dtype=float)
Y1 = np.array([0, .6, 0], dtype=float)
tf = TimeFunction([T1, Y1], inter_mode=TimeFunction.InterConstRight,
dt=0.1)
kernel = HawkesKernelTimeFunc(tf)
hawkes = SimuHawkes(baseline=[.1], end_time=100, verbose=False)
hawkes.set_kernel(0, 0, kernel)
multi_hawkes_1 = SimuHawkesMulti(hawkes, n_simulations=5)
multi_hawkes_1.simulate()
multi_hawkes_2 = SimuHawkesMulti(hawkes, n_simulations=5)
multi_hawkes_2.simulate()
# If no seed are given, realizations must be different
self.assertNotEqual(multi_hawkes_1.timestamps[0][0][0],
multi_hawkes_2.timestamps[0][0][0])
def test_hawkes_negative_intensity(self):
"""...Test simulation with negative kernel
"""
run_time = 40
hawkes = SimuHawkes(n_nodes=1,
end_time=run_time,
verbose=False,
seed=1398)
kernel = HawkesKernelExp(-1.3, .8)
hawkes.set_kernel(0, 0, kernel)
hawkes.set_baseline(0, 0.3)
hawkes.threshold_negative_intensity()
dt = 0.1
hawkes.track_intensity(dt)
hawkes.simulate()
self.assertAlmostEqual(hawkes.tracked_intensity[0].min(), 0)
self.assertAlmostEqual(hawkes.tracked_intensity[0].max(),
hawkes.baseline[0])
self.assertGreater(hawkes.n_total_jumps, 1)
inter_mode=TimeFunction.InterConstRight,
dt=0.1)
kernel1 = HawkesKernelTimeFunc(tf1)
t_values2 = np.linspace(0, 4, 20)
y_values2 = np.maximum(0., np.sin(t_values2) / 4)
tf2 = TimeFunction([t_values2, y_values2])
kernel2 = HawkesKernelTimeFunc(tf2)
baseline = np.array([0.1, 0.3])
hawkes = SimuHawkes(baseline=baseline,
end_time=run_time,
verbose=False,
seed=2334)
hawkes.set_kernel(0, 0, kernel1)
hawkes.set_kernel(0, 1, HawkesKernelExp(.5, .7))
hawkes.set_kernel(1, 1, kernel2)
hawkes.simulate()
em = HawkesEM(4, kernel_size=16, n_threads=8, verbose=False, tol=1e-3)
em.fit(hawkes.timestamps)
fig = plot_hawkes_kernels(em, hawkes=hawkes, show=False)
for ax in fig.axes:
ax.set_ylim([0, 1])
plt.show()
def g2(t):
return np.cos(np.pi * (t / 10 + 1)) + 1.1
t_values = np.linspace(0, 20, 1000)
u_values = [(0.007061, 0.001711), (0.005445, 0.003645), (0.003645, 0.005445),
(0.001790, 0.007390)]
hawkes = SimuHawkes(baseline=[1e-5, 1e-5], seed=1093, verbose=False)
for i, j in itertools.product(range(2), repeat=2):
u1, u2 = u_values[2 * i + j]
y_values = g1(t_values) * u1 + g2(t_values) * u2
kernel = HawkesKernelTimeFunc(t_values=t_values, y_values=y_values)
hawkes.set_kernel(i, j, kernel)
hawkes.end_time = end_time
hawkes.simulate()
ticks = hawkes.timestamps
# And then perform estimation with two basis kernels
kernel_support = 20
n_basis = 2
em = HawkesBasisKernels(kernel_support,
n_basis=n_basis,
kernel_size=kernel_size,
C=C,
n_threads=4,
max_iter=max_iter,
""" 1 dimensional Hawkes process simulation ======================================= """ from tick.plot import plot_point_process from tick.simulation import SimuHawkes, HawkesKernelSumExp import matplotlib.pyplot as plt run_time = 40 hawkes = SimuHawkes(n_nodes=1, end_time=run_time, verbose=False, seed=1398) kernel = HawkesKernelSumExp([.1, .2, .1], [1., 3., 7.]) hawkes.set_kernel(0, 0, kernel) hawkes.set_baseline(0, 1.) dt = 0.01 hawkes.track_intensity(dt) hawkes.simulate() timestamps = hawkes.timestamps intensity = hawkes.tracked_intensity intensity_times = hawkes.intensity_tracked_times _, ax = plt.subplots(1, 2, figsize=(16, 4)) plot_point_process(hawkes, n_points=50000, t_min=2, max_jumps=10, ax=ax[0]) plot_point_process(hawkes, n_points=50000, t_min=2, t_max=20, ax=ax[1]) plt.show()
