Changes between Version 1 and Version 2 of likelihood_l_pdaf
- Timestamp:
- Mar 6, 2018, 4:53:09 PM (7 years ago)
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likelihood_l_pdaf
v1 v2 5 5 The routine `likelihood_l_pdaf` (called `U_likelihood_l` inside the PDAF core routines) is a call-back routine that has to be provided by the user. 6 6 The routine is used in the localized nonlinear filter LNETF and has to compute the likelihood of the observation for a given ensemble member according to the observations used for the local analysis. 7 The likelihood depends on the assumed observation error distribution. For a Gaussian observation error, the likelihood is '''exp(-0.5*(y-Hx)^T^*R^-1^*(y-Hx))''' for the local observations. The vector '''y-HX =''' `resid_l` is prov ed as an input argument. The likelihood has to be returned in the variable `likely_l`.7 The likelihood depends on the assumed observation error distribution. For a Gaussian observation error, the likelihood is '''exp(-0.5*(y-Hx)^T^*R^-1^*(y-Hx))''' for the local observations. The vector '''y-HX =''' `resid_l` is provided as an input argument. The likelihood has to be returned in the variable `likely_l`. 8 8 9 9 This routine is also the place to perform observation localization. To initialize a vector of weights, the routine `PDAF_local_weight` can be called. The procedure is used in the example implementation and also demonstrated in the template routine.