Error raised on negative phase function for tabulated phase function

[Eric-Zhang0]

I tried to use phase function tables outside and I have already converted the original phase functions to the Wigner expansion by following the example of 'convert_libradtran_phase_to_at3d.py'. However, it still raised this error and I don't know whether it is related to the issue that I could not convert phase functions successfully.

[JRLoveridge]

The phase function should be positive, so they aren't being converted correctly. You can check whether the phase function is reconstructed correctly from your converted coefficients by using at3d.util.get_phase_function. Given the large negative value, one thing to double check is the normalization. The Legendre coefficients should include the (2i + 1) factor, for the ith Legendre coefficient, so an asymmetry parameter of 0.85 will correspond to a Legendre coefficient of 0.85(2*1+1) = 2.55.

[Eric-Zhang0]

Thanks for your kind advice and I will try it agian.