Nicolas Minesi

@dcmvdbekerom any news on that? Is the issue still open?

The following example works now on the branch `develop`: ```python from radis import calc_spectrum s = calc_spectrum( wavenum_min=2245, wavenum_max=2250, Tgas=700, path_length=0.1, mole_fraction={"CO":0.4, "CO2":0.4}, isotope=1, databank="hitran", export_lines=True, ) s.plot("absorbance") ``` It...

@saradelahaie I hope this issue is not hindering your progress. Let me know if this is the case. Otherwise I'll come back later on this issue (and secretly hope someone...

Labeled "Good first issue" since Erwan provided a method to solve the problem

If you can understand the steps described by Erwan, it means you're good enough at maths :)

In the example, the slit_size is a float. For instance, you can set it to `slit_size=1`

@code29563 could be interesting for you to consult

@erwanp @E-W-Jones what is the status of this PR?

Merging because this branch passed the tests :)

@Rockyuo666, I tried the following example and it worked. Are you still having performance issues or bugs? ```python from radis import SpectrumFactory wmin, wmax = 2383.8, 2384.9 sf = SpectrumFactory(wavenum_min=wmin,...