Catalog Postprocessing

For samples of galaxies or applications like galaxy mapping, it’s desirable to combine the results of all the completed SED fits into a single file. We provide a function for this: lightning.postprocessing.postprocess_catalog. The function takes lists of “result” and “model” files and collates the results into a single HDF5 catalog. The result files are expected to be HDF5 files with a specific format.

For solver_mode='mcmc', the chains are also expected to be in HDF5 format, with the following structure:

mcmc
├── logprob_samples (Nsamples)
├── samples (Nsamples, Nparams)
└── autocorr (Nparams)

Whereas for solver_mode='mle', the results are expected to be formated as:

res
├── bestfit (Nparams)
└── chi2_best ()

The model files can be either JSON or pickle files, selected by the model_mode keyword. The final HDF5 catalog file is generally structured as follows:

└──sourcename
    ├── mcmc
    │   ├── logprob_samples (Nsamples)
    │   └── samples (Nsamples, Nparams)
    ├── parameters
    │   ├── modelname
    │   │   └── parametername
    │   │       ├── best ()
    │   │       ├── hi ()
    │   │       ├── lo ()
    │   │       └── med ()
    └── properties
        ├── filter_labels (Nfilters)
        ├── lnu (Nfilters)
        ├── lnu_unc (Nfilters)
        ├── lumdist ()
        ├── mstar
        │   ├── best ()
        │   ├── hi ()
        │   ├── lo ()
        │   └── med ()
        ├── redshift ()
        └── pvalue ()

where e.g., MCMC keys and parameter quantiles are omitted when dealing with MLE results. See Postprocessing in the detailed API reference for further information.