Module HawkesPyLib.core.intensity

Functions

def generate_eval_grid(step_size: float, T: float) ‑> numpy.ndarray

Generates an equidistant grid in the closed interval [0, T] with step size given by step_size.

Args

step_size : float
Step size of the equidistant grid.
T : float
End point of the equidistant grid (the last value).

Returns

np.ndarray
1d array equidistant grid between from 0 to t with step size.
def uvhp_expo_intensity(sample_vec: numpy.ndarray, grid: numpy.ndarray, mu: float, eta: float, theta: float) ‑> numpy.ndarray

Evaluation of the intensity function of a univariate Hawkes process with single exponential kernel

Args

sample_vec : np.ndarray
Jump times of the Hawkes process. Must be non-negative and in ascending order!
grid : np.ndarray
Times at which the intensity function is evaluated at. Must be non-negative and in ascending order
mu : float
Background intensity of the Hawkes process, mu > 0
eta : float
Branching ratio of the Hawkes process, 0 > eta < 1
theta : float
Decay speed of the single exponential kernel, theta > 0

Returns

np.ndarray
A 2d numpy array of timestamps (column 0) and corresponding intensity values (column 1)
def uvhp_sum_expo_intensity(sample_vec: numpy.ndarray, grid: numpy.ndarray, mu: float, eta: float, theta_vec: numpy.ndarray) ‑> numpy.ndarray

Evaluation of the intensity function of a univariate Hawkes process with P-sum exponential kernel

Args

sample_vec : np.ndarray
Jump times of the Hawkes process. Must be non-negative and in ascending order!
grid : np.ndarray
Times at which the intensity function is evaluated at. Must be non-negative and in ascending order
mu : float
Background intensity of the Hawkes process, mu > 0
eta : float
Branching ratio of the Hawkes process, 0 > eta < 1
theta_vec : np.ndarray
Array of decay speeds of the P-sum exponential kernel, theta_k > 0

Returns

np.ndarray
A 2d numpy array of timestamps (column 0) and corresponding intensity values (column 1)
def uvhp_approx_powl_cutoff_intensity(sample_vec: numpy.ndarray, grid: numpy.ndarray, mu: float, eta: float, alpha: float, tau: float, m: float, M: int) ‑> numpy.ndarray

Evaluation of the intensity function of a univariate Hawkes process with approximate power-law kernel with smooth cutoff component

Args

sample_vec : np.ndarray
Jump times of the Hawkes process. Must be non-negative and in ascending order!
grid : np.ndarray
Times at which the intensity function is evaluated at. Must be non-negative and in ascending order
mu : float
Background intensity of the Hawkes process, mu > 0
eta : float
Branching ratio of the Hawkes process, 0 > eta < 1
alpha : float
Power-law coefficient, alpha > 0
tau : float
Approximate location of cutoff, tau > 0
m : float
Approximate power-law parameter, m > 0
M : int
Number of weighted exponential kernels that approximate the power-law

Returns

np.ndarray
A 2d numpy array of timestamps (column 0) and corresponding intensity values (column 1)
def uvhp_approx_powl_intensity(sample_vec: numpy.ndarray, grid: numpy.ndarray, mu: float, eta: float, alpha: float, tau: float, m: float, M: int) ‑> numpy.ndarray

Evaluation of the intensity function of a univariate Hawkes process with approximate power-law kernel.

Args

sample_vec : np.ndarray
Jump times of the Hawkes process. Must be non-negative and in ascending order!
grid : np.ndarray
Times at which the intensity function is evaluated at. Must be non-negative and in ascending order.
mu : float
Background intensity of the Hawkes process, mu > 0
eta : float
Branching ratio of the Hawkes process, 0 > eta < 1
alpha : float
Power-law coefficient, alpha > 0
tau : float
Approximate location of cutoff, tau > 0
m : float
Approximate power-law parameter, m > 0
M : int
Number of weighted exponential kernels that approximate the power-law

Returns

np.ndarray
A 2d numpy array of timestamps (column 0) and corresponding intensity values (column 1)