Plot HITRAN cross-sections

Parse HITRAN ([HITRAN-2016]) cross-sections manually downloaded from https://hitran.org/xsc/ turn them into a Radis Spectrum, and plot the resulting transmittance rescaled for arbitrary mole fractions or path length

Text(0.5, 1.1577454804419003, 'CH3COCH3')

from radis import Spectrum
from radis.phys.units import Unit as u

### In this example:
# The cross-section "CH3COCH3_233.4_375.2_700.0-1780.0_13.xsc" was manually downloaded by RADIS developer
# For another cross-section: 1/perform manual download from HITRAN and 2/ adapt `path_to_datafile`
from radis.test.utils import getTestFile

path_to_datafile = getTestFile("CH3COCH3_233.4_375.2_700.0-1780.0_13.xsc")

# Temperature and pressure are given by the cross-section file used above: 233.4 K; 375.2 Torr
# Mole fraction and path length can be recomputed arbitrarily :
conditions = {"mole_fraction": 0.1, "path_length": 20 * u("mm")}

s = Spectrum.from_xsc(path_to_datafile, conditions)

s.plot("transmittance_noslit", lw=2)

# Rescale for other path lengths, and plot :
s.rescale_path_length(100 * u("mm")).plot(nfig="same")

import matplotlib.pyplot as plt

plt.title(s.c["molecule"])