Opened 15 years ago
Closed 15 years ago
#232 closed upgrade (Done)
IS4VAR Revisited: Preconditioning
| Reported by: | arango | Owned by: | arango |
|---|---|---|---|
| Priority: | major | Milestone: | Adjoint Based Algorithms |
| Component: | Adjoint | Version: | 3.2 |
| Keywords: | Cc: |
Description
This is a big update for the incremental, strong constraint, 4DVar data assimilation algorithm (IS4DVAR). A new preconditioning conjugate gradient algorithm based on the Lanczos methodology is implemented. Two versions of the preconditioning are available:
- Spectral limited-memory preconditioner (Fisher, 1998)
- Ritz limited-memory preconditioning (Tshimanga et al., 2008)
Many thanks to Andy Moore for his help on implementing and testing the new algorithm.
Andy wrote a nice technical description and usage guidelines in wikiROMS for the new algorithm.
Change History (1)
comment:1 by , 15 years ago
| Resolution: | → Done |
|---|---|
| Status: | new → closed |
| Summary: | IS4VAR revisited with preconditioning → IS4VAR Revisited: Preconditioning |
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