# ARTS built-in documentation server

## Workspace Method retrievalAddAbsSpecies

### Description

Adds an absorption species to the retrieval quantities. Similar to jacobianAddAbsSpecies but also sets the corresponding block in covmat_sx to the matrices provided in covmat_block and covmat_inv_block. The dimensions of covmat_block are required to agree with the dimensions of the retrieval grid. covmat_inv_block must be either empty or the same dimension as covmat_block. If provided, this matrix will be used as the inverse for the covariance matrix block and numerical inversion of this block is thus avoided. Note, however, that this is only effective if this block is uncorrelated with any other retrieval quantity. For number and order of elements added to x, see jacobianAddAbsSpecies.

**Authors: **Simon Pfreundschuh

### Synopsis

retrievalAddAbsSpecies( | covmat_sx, jacobian_quantities, jacobian_agenda, atmosphere_dim, covmat_block, covmat_inv_block, p_grid, lat_grid, lon_grid, g1, g2, g3, species, unit, for_species_tag ) |

### Variables

OUT+IN | covmat_sx | (CovarianceMatrix) | Covariance matrix of a priori distribution This covariance matrix describes the Gaussian a priori distribution for an OEM retrieval. |

OUT+IN | jacobian_quantities | (ArrayOfRetrievalQuantity) | The retrieval quantities in the Jacobian matrix. |

OUT+IN | jacobian_agenda | (Agenda) | Pure numerical Jacobian calculation agenda. |

IN | atmosphere_dim | (Index) | The atmospheric dimensionality (1-3). |

IN | covmat_block | (Sparse) | Holds matrices used to set blocks in covmat_sx and covmat_se. |

IN | covmat_inv_block | (Sparse) | Holds matrices used to set the inverse blocks in covmat_sx and covmat_se. |

IN | p_grid | (Vector) | The pressure grid. |

IN | lat_grid | (Vector) | The latitude grid. |

IN | lon_grid | (Vector) | The longitude grid. |

GIN | g1 | (Vector) | Pressure retrieval grid. |

GIN | g2 | (Vector) | Latitude retrieval grid. |

GIN | g3 | (Vector) | Longitude retreival grid. |

GIN | species | (String) | The species tag of the retrieval quantity. |

GIN | unit | (String, Default: "rel") | Retrieval unit. See above. |

GIN | for_species_tag | (Index, Default: 1) | Index-bool for acting on species tags or species. |