rlabbe / filterpy

Python Kalman filtering and optimal estimation library. Implements Kalman filter, particle filter, Extended Kalman filter, Unscented Kalman filter, g-h (alpha-beta), least squares, H Infinity, smoothers, and more. Has companion book 'Kalman and Bayesian Filters in Python'.
MIT License
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can rts_smoother return cov(\theta_t, \theta_{t-1}) rather than just cov(\theta_t)? #207

Open BobZiyangDing opened 4 years ago

BobZiyangDing commented 4 years ago

It seems like that when running rts_smoother, it can also calculate $Cov(\thetat, \theta{t-1})$, when $thetat, \theta{t-1}$ are all multidimensional yet same dimensional. However, rts_smoother only return the $Cov(\theta_t)$, which is the covariance of every dimension within a state vector itself, but not every pair of dimensions across states at consecutive time step. Can we add that functionality? Or is it already there?