radis.io.hitran module

RADIS Hitran Functions; based on Common API hitranapi.py

fetch_hitran(molecule, extra_params=None, local_databases=None, databank_name='HITRAN-{molecule}', isotope=None, load_wavenum_min=None, load_wavenum_max=None, columns=None, cache=True, verbose=True, clean_cache_files=True, return_local_path=False, engine='default', output='pandas', parallel=True, parse_quanta=True)[source]

Download all HITRAN lines from HITRAN website. Unzip and build a HDF5 file directly.

Returns a Pandas DataFrame containing all lines.

Parameters:

  • molecule (str) – one specific molecule name, listed in HITRAN molecule metadata. See https://hitran.org/docs/molec-meta/ Example: “H2O”, “CO2”, etc.

  • local_databases (str) – where to create the RADIS HDF5 files. Default "~/.radisdb/hitran". Can be changed in radis.config["DEFAULT_DOWNLOAD_PATH"] or in ~/radis.json config file

  • databank_name (str) – name of the databank in RADIS Configuration file Default "HITRAN-{molecule}"

  • isotope (str) – load only certain isotopes : '2', '1,2', etc. If None, loads everything. Default None.

  • load_wavenum_min, load_wavenum_max (float (cm-1)) – load only specific wavenumbers.

  • columns (list of str) – list of columns to load. If None, returns all columns in the file.

  • extra_params (‘all’ or None) – Downloads all additional columns available in the HAPI database for the molecule including parameters like gamma_co2, n_co2 that are required to calculate spectrum in co2 diluent. For eg:

    from radis.io.hitran import fetch_hitran
df = fetch_hitran('CO', extra_params='all', cache='regen') # cache='regen' to regenerate new database with additional columns
Other Parameters:

  • cache (True, False, 'regen' or 'force') – if True, use existing HDF5 file. If False or 'regen', rebuild it. If 'force', raise an error if cache file cannot be used (useful for debugging). Default True.

  • verbose (bool)

  • clean_cache_files (bool) – if True clean downloaded cache files after HDF5 are created.

  • return_local_path (bool) – if True, also returns the path of the local database file.

  • engine (‘pytables’, ‘vaex’, ‘default’) – which HDF5 library to use. If ‘default’ use the value from ~/radis.json

  • output (‘pandas’, ‘vaex’, ‘jax’) – format of the output DataFrame. If 'jax', returns a dictionary of jax arrays. If 'vaex', output is a vaex.dataframe.DataFrameLocal

    Note

    Vaex DataFrames are memory-mapped. They do not take any space in RAM and are extremely useful to deal with the largest databases.

  • parallel (bool) – if True, uses joblib.parallel to load database with multiple processes

  • parse_quanta (bool) – if True, parse local & global quanta (required to identify lines for non-LTE calculations ; but sometimes lines are not labelled.)

Returns:

  • df (pd.DataFrame or vaex.dataframe.DataFrameLocal) – Line list A HDF5 file is also created in local_databases and referenced in the RADIS config file with name databank_name

  • local_path (str) – path of local database file if return_local_path

Examples

from radis.io.hitran import fetch_hitran
df = fetch_hitran("CO")
print(df.columns)
>>> Index(['id', 'iso', 'wav', 'int', 'A', 'airbrd', 'selbrd', 'El', 'Tdpair',
    'Pshft', 'gp', 'gpp', 'branch', 'jl', 'vu', 'vl'],
    dtype='object')

Explore Line Database Parameters

Explore Line Database Parameters

Download the HITRAN database

Download the HITRAN database

Notes

if using load_only_wavenum_above/below or isotope, the whole database is anyway downloaded and uncompressed to local_databases fast access .HDF5 files (which will take a long time on first call). Only the expected wavenumber range & isotopes are returned. The .HFD5 parsing uses hdf2df()

if a registered entry already exists and radis.config["ALLOW_OVERWRITE"] is True: - if any situation arises where the databank needs to be re-downloaded, the possible urls are attempted in their usual order of preference, as if the databank hadn’t been registered, rather than directly re-downloading from the same url that was previously registered, in case e.g. a new linelist has been uploaded since the databank was previously registered - If no partition function file is registered, e.g because one wasn’t available server-side when the databank was last registered, an attempt is still made again to download it, to account for e.g. the case where one has since been uploaded

See also

fetch_hitemp(), fetch_exomol(), fetch_geisa(), fetch_kurucz(), hdf2df(), fetch_databank()