Assuming you have Python installed with the Anaconda distribution just use:
pipinstallradis
That’s it! You can now run your first example below.
If you encounter any problem or if you need to upgrade, please refer to the
detailed installation procedure. If you don’t have a Python
environment, try 🌱 RADIS Online first !
Calculate a CO equilibrium spectrum from the [HITRAN-2020] database, using the
calc_spectrum() function. Lines are downloaded automatically
using Astroquery (based on [HAPI]). Output is a
Spectrum object:
fromradisimportcalc_spectrums=calc_spectrum(1900,2300,# cm-1molecule='CO',isotope='1,2,3',pressure=1.01325,# barTgas=700,# Kmole_fraction=0.1,path_length=1,# cmdatabank='hitran',# or 'hitemp', 'geisa', 'exomol')s.apply_slit(0.5,'nm')# simulate an experimental slits.plot('radiance')
Calculate a CO nonequilibrium spectrum from the HITRAN database, with
arbitrary units (on your first call, this will compute and
store the CO(X) rovibrational energies):
fromastropyimportunitsasus2=calc_spectrum(1900/u.cm,2300/u.cm,molecule='CO',isotope='1,2,3',pressure=1.01325*u.bar,Tvib=700*u.K,Trot=300*u.K,mole_fraction=0.1,path_length=1*u.cm,databank='hitran',# or 'hitemp', 'geisa', 'exomol')s2.apply_slit(0.5,'nm')s2.plot('radiance',nfig='same')# compare with previous
Fit a non-LTE spectrum with multiple fit parameters
The Quick Start examples automatically downloaded the line databases from [HITRAN-2020], which is valid for temperatures below 700 K.
For high temperature cases, you may need to use other line databases such as
[HITEMP-2010] (typically T < 2000 K) or [CDSD-4000] (T < 5000 K). These databases must be described in a ~/radis.jsonConfiguration file.
Note
📣 starting from radis==0.9.30 you can also download HITEMP and ExoMol directly. Just use databank='hitemp'
or databank='exomol' in the initial example. This will automatically download, unzip and setup the database
files in a ~/.radisdb folder.
More complex examples will require to use the SpectrumFactory
class, which is the core of RADIS line-by-line calculations.
Refer to the Examples and Example Gallery sections for more examples, and to the
User Documentation for more details on the code.
You can also ask questions on the Q&A Forum
or on the community chats on Gitter or
Slack
Alternatively, you can also run RADIS directly in the browser with the
RADIS Interactive Examples project.
For instance, run the Quick Start example on the link below:
Or use 🌱 RADIS-lab to start a full online environment for advanced spectrum processing
and comparison with experimental data :
RADIS is built on the shoulders of many state-of-the-art packages and databases. If using RADIS
to compute spectra, make sure you cite all of them, for proper reproducibility and acknowledgement of
the work ! See How to cite?
This is the core of RADIS: it calculates the spectral densities for a homogeneous
slab of gas, and returns a Spectrum object. Calculations
are performed within the SpectrumFactory class.
calc_spectrum() is a high-level wrapper to
SpectrumFactory for most simple cases.
This module takes several Spectrum objects
as input and combines then along the line-of-sight (SerialSlabs())
or at the same spatial position (MergeSlabs()), to reproduce
line-of-sight experiments. The module allows combination of Spectra such as:
This module contains the Spectrum object itself, with several methods that can be
applied after the Spectrum was calculated: rescale, apply instrumental slit function,
store or retrieve from a Spectrum database, plot or compare with another Spectrum object.
