pyPDAF.PDAF.assimilate_lnetf

pyPDAF.PDAF.assimilate_lnetf()

It is recommended to use pyPDAF.PDAF.localomi_assimilate() or pyPDAF.PDAF.localomi_assimilate_lnetf_nondiagR().

PDAF-OMI modules require fewer user-supplied functions and improved efficiency.

Local Nonlinear Ensemble Transform Filter (LNETF) [1] for a single DA step. The nonlinear filter computes the distribution up to the second moment similar to Kalman filters but it uses a nonlinear weighting similar to particle filters. This leads to an equal weights assumption for the prior ensemble at each step. This function should be called at each model time step.

The function is a combination of pyPDAF.PDAF.put_state_lnetf() and pyPDAF.PDAF.get_state().

This function executes the user-supplied function in the following sequence:

  1. py__collect_state_pdaf

  2. py__prepoststep_state_pdaf

  3. py__init_n_domains_p_pdaf

  4. py__init_dim_obs_pdaf

  5. py__obs_op_pdaf (for each ensemble member)

  6. loop over each local domain:

    1. py__init_dim_l_pdaf

    2. py__init_dim_obs_l_pdaf

    3. py__g2l_state_pdaf

    4. py__init_obs_l_pdaf

    5. py__g2l_obs_pdaf (localise each ensemble member in observation space)

    6. py__likelihood_l_pdaf

    7. core DA algorithm

    8. py__l2g_state_pdaf

  7. py__prepoststep_state_pdaf

  8. py__distribute_state_pdaf

  9. py__next_observation_pdaf

Deprecated since version 1.0.0: This function is replaced by pyPDAF.PDAF.localomi_assimilate() and pyPDAF.PDAF.localomi_assimilate_lnetf_nondiagR()

References

Parameters:

  • py__collect_state_pdaf (Callable[dim_p:int, state_p : ndarray[tuple[dim_p], np.float64]]) –

    Routine to collect a state vector

    Callback Parameters
    • dim_pint

      • pe-local state dimension

    • state_pndarray[tuple[dim_p], np.float64]

      • local state vector

    Callback Returns
    • state_pndarray[tuple[dim_p], np.float64]

      • local state vector

  • py__distribute_state_pdaf (Callable[dim_p:int, state_p : ndarray[tuple[dim_p], np.float64]]) –

    Routine to distribute a state vector

    Callback Parameters
    • dim_pint

      • pe-local state dimension

    • state_pndarray[tuple[dim_p], np.float64]

      • local state vector

    Callback Returns
    • state_pndarray[tuple[dim_p], np.float64]

      • local state vector

  • py__init_dim_obs_pdaf (Callable[step:int, dim_obs_p:int]) –

    Initialize dimension of observation vector

    Callback Parameters
    • stepint

      • current time step

    • dim_obs_pint

      • dimension of observation vector

    Callback Returns
    • dim_obs_pint

      • dimension of observation vector

  • py__obs_op_pdaf (Callable[step:int, dim_p:int, dim_obs_p:int, state_p : ndarray[tuple[dim_p], np.float64], m_state_p : ndarray[tuple[dim_obs_p], np.float64]]) –

    Observation operator

    Callback Parameters
    • stepint

      • Current time step

    • dim_pint

      • Size of state vector (local part in case of parallel decomposed state)

    • dim_obs_pint

      • Size of observation vector

    • state_pndarray[tuple[dim_p], np.float64]

      • Model state vector

    • m_state_pndarray[tuple[dim_obs_p], np.float64]

      • Observed state vector (i.e. the result after applying the observation operator to state_p)

    Callback Returns
    • m_state_pndarray[tuple[dim_obs_p], np.float64]

      • Observed state vector (i.e. the result after applying the observation operator to state_p)

  • py__init_obs_l_pdaf (Callable[domain_p:int, step:int, dim_obs_l:int, observation_l : ndarray[tuple[dim_obs_l], np.float64]]) –

    Init. observation vector on local analysis domain

    Callback Parameters
    • domain_pint

      • Index of current local analysis domain

    • stepint

      • Current time step

    • dim_obs_lint

      • Local size of the observation vector

    • observation_lndarray[tuple[dim_obs_l], np.float64]

      • Local vector of observations

    Callback Returns
    • observation_lndarray[tuple[dim_obs_l], np.float64]

      • Local vector of observations

  • py__prepoststep_pdaf (Callable[step:int, dim_p:int, dim_ens:int, dim_ens_p:int, dim_obs_p:int, state_p : ndarray[tuple[dim_p], np.float64], uinv : ndarray[tuple[dim_ens-1, dim_ens-1], np.float64], ens_p : ndarray[tuple[dim_p, dim_ens], np.float64], flag:int]) –

    User supplied pre/poststep routine

    Callback Parameters
    • stepint

      • current time step (negative for call after forecast)

    • dim_pint

      • pe-local state dimension

    • dim_ensint

      • size of state ensemble

    • dim_ens_pint

      • pe-local size of ensemble

    • dim_obs_pint

      • pe-local dimension of observation vector

    • state_pndarray[tuple[dim_p], np.float64]

      • pe-local forecast/analysis state (the array ‘state_p’ is not generally not initialized in the case of seik. it can be used freely here.)

    • uinvndarray[tuple[dim_ens-1, dim_ens-1], np.float64]

      • inverse of matrix u

    • ens_pndarray[tuple[dim_p, dim_ens], np.float64]

      • pe-local state ensemble

    • flagint

      • pdaf status flag

    Callback Returns
    • state_pndarray[tuple[dim_p], np.float64]

      • pe-local forecast/analysis state (the array ‘state_p’ is not generally not initialized in the case of seik. it can be used freely here.)

    • uinvndarray[tuple[dim_ens-1, dim_ens-1], np.float64]

      • inverse of matrix u

    • ens_pndarray[tuple[dim_p, dim_ens], np.float64]

      • pe-local state ensemble

  • py__likelihood_l_pdaf (Callable[domain_p:int, step:int, dim_obs_l:int, obs_l : ndarray[tuple[dim_obs_l], np.float64], resid_l : ndarray[tuple[dim_obs_l], np.float64], likely_l:float]) –

    Compute observation likelihood for an ensemble member

    Callback Parameters
    • domain_pint

      • Index of current local analysis domain

    • stepint

      • Current time step

    • dim_obs_lint

      • Number of local observations at current time step (i.e. the size of the local observation vector)

    • obs_lndarray[tuple[dim_obs_l], np.float64]

      • Local vector of observations

    • resid_lndarray[tuple[dim_obs_l], np.float64]

      • nput vector holding the local residual

    • likely_lfloat

      • Output value of the local likelihood

    Callback Returns
    • likely_lfloat

      • Output value of the local likelihood

  • py__init_n_domains_p_pdaf (Callable[step:int, n_domains_p:int]) –

    Provide number of local analysis domains

    Callback Parameters
    • stepint

      • current time step

    • n_domains_pint

      • pe-local number of analysis domains

    Callback Returns
    • n_domains_pint

      • pe-local number of analysis domains

  • py__init_dim_l_pdaf (Callable[step:int, domain_p:int, dim_l:int]) –

    Init state dimension for local ana. domain

    Callback Parameters
    • stepint

      • current time step

    • domain_pint

      • current local analysis domain

    • dim_lint

      • local state dimension

    Callback Returns
    • dim_lint

      • local state dimension

  • py__init_dim_obs_l_pdaf (Callable[domain_p:int, step:int, dim_obs_f:int, dim_obs_l:int]) –

    Initialize dim. of obs. vector for local ana. domain

    Callback Parameters
    • domain_pint

      • index of current local analysis domain

    • stepint

      • current time step

    • dim_obs_fint

      • full dimension of observation vector

    • dim_obs_lint

      • local dimension of observation vector

    Callback Returns
    • dim_obs_lint

      • local dimension of observation vector

  • py__g2l_state_pdaf (Callable[step:int, domain_p:int, dim_p:int, state_p : ndarray[tuple[dim_p], np.float64], dim_l:int, state_l : ndarray[tuple[dim_l], np.float64]]) –

    Get state on local ana. domain from full state

    Callback Parameters
    • stepint

      • current time step

    • domain_pint

      • current local analysis domain

    • dim_pint

      • pe-local full state dimension

    • state_pndarray[tuple[dim_p], np.float64]

      • pe-local full state vector

    • dim_lint

      • local state dimension

    • state_lndarray[tuple[dim_l], np.float64]

      • state vector on local analysis domain

    Callback Returns
    • state_lndarray[tuple[dim_l], np.float64]

      • state vector on local analysis domain

  • py__l2g_state_pdaf (Callable[step:int, domain_p:int, dim_l:int, state_l : ndarray[tuple[dim_l], np.float64], dim_p:int, state_p : ndarray[tuple[dim_p], np.float64]]) –

    Init full state from state on local analysis domain

    Callback Parameters
    • stepint

      • current time step

    • domain_pint

      • current local analysis domain

    • dim_lint

      • local state dimension

    • state_lndarray[tuple[dim_l], np.float64]

      • state vector on local analysis domain

    • dim_pint

      • pe-local full state dimension

    • state_pndarray[tuple[dim_p], np.float64]

      • pe-local full state vector

    Callback Returns
    • state_pndarray[tuple[dim_p], np.float64]

      • pe-local full state vector

  • py__g2l_obs_pdaf (Callable[domain_p:int, step:int, dim_obs_f:int, dim_obs_l:int, mstate_f : ndarray[tuple[dim_p], np.intc], dim_p:int, mstate_l : ndarray[tuple[dim_l], np.intc], dim_l:int]) –

    Restrict full obs. vector to local analysis domain

    Callback Parameters
    • domain_pint

      • Index of current local analysis domain

    • stepint

      • Current time step

    • dim_obs_fint

      • Size of full observation vector for model sub-domain

    • dim_obs_lint

      • Size of observation vector for local analysis domain

    • mstate_fndarray[tuple[dim_p], np.intc]

      • Full observation vector for model sub-domain

    • dim_pint

      • Size of full observation vector for model sub-domain

    • mstate_lndarray[tuple[dim_l], np.intc]

      • Observation vector for local analysis domain

    • dim_lint

      • Size of observation vector for local analysis domain

    Callback Returns
    • mstate_lndarray[tuple[dim_l], np.intc]

      • Observation vector for local analysis domain

  • py__next_observation_pdaf (Callable[stepnow:int, nsteps:int, doexit:int, time:float]) –

    Provide time step and time of next observation

    Callback Parameters
    • stepnowint

      • number of the current time step

    • nstepsint

      • number of time steps until next obs

    • doexitint

      • whether to exit forecasting (1 for exit)

    • timefloat

      • current model (physical) time

    Callback Returns
    • nstepsint

      • number of time steps until next obs

    • doexitint

      • whether to exit forecasting (1 for exit)

    • timefloat

      • current model (physical) time

Returns:

flag – Status flag

Return type:

int