NEDAS.models.lotka_volterra.lotka_volterra_model module

class NEDAS.models.lotka_volterra.lotka_volterra_model.LotkaVolterraModel(**kwargs)[source]

Bases: OdeModel

The competitive Lotka-Volterra (predator-prey) model of 4 species, with the chaotic parameters of Vano et al. (2006): dx_i/dt = r_i x_i (1 - sum_j A_ij x_j).

As in DAPPER mods/LotkaVolterra. The populations are positive, a test for DA of bounded variables.

Parameters:

r (list) – growth rates
A (list of lists) – interaction coefficients

r: list

A: list

property state_size: int: length of the state vector

x0() → ndarray[source]: a reference state, perturbed and spun up to start the truth and the ensemble

dxdt(x: ndarray) → ndarray[source]: the time derivative of the state (for an ODE stepped by step)