Use Custom Abundances

Custom isotopologue abundances can be defined, to model non-terrestrial atmospheres.

Abundances are read and set directly in the SpectrumFactory using the get_abundance() and set_abundance() methods.

Below, we compute a CO2 spectrum with custom abundances for the two main terrestrial isotopes (12C-16O2 ; 13C-16O2)

See Also

MolParams

from radis.test.utils import setup_test_line_databases

setup_test_line_databases()  # creates "HITEMP-CO2-TEST" for this example

from radis import SpectrumFactory

sf = SpectrumFactory(
    2284.2,
    2284.6,
    wstep=0.001,  # cm-1
    pressure=20 * 1e-3,  # bar
    mole_fraction=400e-6,
    molecule="CO2",
    isotope="1,2",
    verbose=False,
)
sf.load_databank("HITEMP-CO2-TEST")

Added HITRAN-CO2-TEST database in /home/docs/radis.json
Added HITRAN-CO-TEST database in /home/docs/radis.json
Added HITEMP-CO2-TEST database in /home/docs/radis.json
Added HITEMP-CO2-HAMIL-TEST database in /home/docs/radis.json
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/db/molparam.py:252: FutureWarning: The 'delim_whitespace' keyword in pd.read_csv is deprecated and will be removed in a future version. Use ``sep='\s+'`` instead
  df = pd.read_csv(file, comment="#", delim_whitespace=True)
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/misc/warning.py:427: MissingReferenceWarning: Missing doi for CDSD-HITEMP. Use HITEMP-2010?
  warnings.warn(WarningType(message))
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/api/tools.py:280: FutureWarning: Downcasting behavior in `replace` is deprecated and will be removed in a future version. To retain the old behavior, explicitly call `result.infer_objects(copy=False)`. To opt-in to the future behavior, set `pd.set_option('future.no_silent_downcasting', True)`
  new_col = df["branch"].replace(mapping)

To explicitly identify the isotopes we can use the molparam attribute the Factory

print(sf.molparam.get("CO2", 1, "isotope_name"))  # >> (12C)(16O)2
print(sf.molparam.get("CO2", 2, "isotope_name"))  # >> (13C)(16O)2

(12C)(16O)2
(13C)(16O)2

Print the default abundance of the CO2 isotopes, compute a spectrum

print("Abundance of CO2[1,2]", sf.get_abundance("CO2", [1, 2]))
sf.eq_spectrum(2000).plot("abscoeff")

Abundance of CO2[1,2] [[0.984204 ]
 [0.0110574]]
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/misc/warning.py:427: PerformanceWarning: 'object' type column found in database, calculations and memory usage would be faster with a numeric type. Possible solution is to not use 'save_memory' and convert the columns to dtype.
  warnings.warn(WarningType(message))

<matplotlib.lines.Line2D object at 0x7fbdfe9e2830>

Set the abundance of CO2(626) to 0.8; and the abundance of CO2(636) to 0.2 (arbitrary):

sf.set_abundance("CO2", [1, 2], [0.8, 0.2])
print("New abundance of CO2[1,2]", sf.get_abundance("CO2", [1, 2]))

sf.eq_spectrum(2000).plot("abscoeff", nfig="same")

New abundance of CO2[1,2] [[0.8]
 [0.2]]
/home/docs/checkouts/readthedocs.org/user_builds/radis/checkouts/latest/radis/misc/warning.py:427: PerformanceWarning: 'object' type column found in database, calculations and memory usage would be faster with a numeric type. Possible solution is to not use 'save_memory' and convert the columns to dtype.
  warnings.warn(WarningType(message))
findfont: Font family ['sans-serif'] not found. Falling back to DejaVu Sans.
findfont: Generic family 'sans-serif' not found because none of the following families were found: Helvetica, Bitstream Vera Sans, Lucida Grande, Verdana, Geneva, Lucid, Arial, Avant Garde, sans-serif

<matplotlib.lines.Line2D object at 0x7fbdfe79e7d0>