PetscDAEnsembleAnalysis

Executes the analysis (update) step using sparse observation matrix H

Synopsis

PetscErrorCode PetscDAEnsembleAnalysis(PetscDA da, Vec observation, Mat H)

Collective

Input Parameters

• da - the PetscDA context

• observation - observation vector y in R^P

• H - observation operator matrix (P x N), sparse AIJ format

Notes

The observation matrix H maps from state space (N dimensions) to observation space (P dimensions): y = H*x + noise

H must be a sparse AIJ matrix

For identity observations (observe entire state), use an identity matrix for H. For partial observations, set appropriate rows and columns to observe specific state components. On return, the ensemble matrix held by da has been updated in place: every member has been replaced by its analysis update. Read the analysis state with PetscDAEnsembleGetMember() or PetscDAEnsembleComputeMean().

See Also

PetscDA: Data Assimilation, PetscDA, PETSCDALETKF, PetscDAEnsembleForecast(), PetscDASetObsErrorVariance(), PetscDAEnsembleGetMember(), PetscDAEnsembleComputeMean()

Level

intermediate

Location

src/ml/da/impls/ensemble/daensemble.c

Examples

src/ml/da/tutorials/ex1.c
src/ml/da/tutorials/ex2.c
src/ml/da/tutorials/ex4.c
src/ml/da/tutorials/ex3.c

Implementations

PetscDAEnsembleAnalysis_LETKF() in src/ml/da/impls/ensemble/letkf/letkfilter.c

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Index of all PetscDA routines
Table of Contents for all manual pages
Index of all manual pages