Enkf
polars_ts.bayesian.enkf
Ensemble Kalman Filter (EnKF).
Monte Carlo ensemble propagation through nonlinear transition and observation functions. Scalable to high-dimensional states where maintaining a full covariance matrix is infeasible.
Reference
Evensen (2003). The Ensemble Kalman Filter: theoretical formulation and practical implementation.
EnsembleKalmanFilter
Ensemble Kalman Filter for nonlinear state-space models.
Parameters
f
State transition function f(x) -> x_next.
h
Observation function h(x) -> y.
Q
Process noise covariance (n, n).
R
Observation noise covariance (m, m).
x0
Initial state mean (n,).
P0
Initial state covariance (n, n).
n_ensemble
Number of ensemble members. Default 50.
seed
Random seed for reproducibility.
filter(y)
Run the EnKF forward pass.
Parameters
y
Observations (T,) or (T, m). Use np.nan for missing.
Returns
KalmanResult