line_ratio#

fiasco.line_ratio(ion, numerator, denominator, density: Unit('1 / cm3'), **kwargs)[source]#

Theoretical line ratio for one or more bound-bound transitions as a function of temperature and density.

Parameters:

  • ion (Ion) – Ion used to compute the contribution function.

  • numerator (array-like of Quantity, str or mix of both) – Bound-bound transition wavelengths or transition labels for the numerator and denominator. If multiple transitions are provided, their contribution functions are summed before taking the ratio. Transition labels must exactly match entries in ion.transitions.label[ion.transitions.is_bound_bound].

  • denominator (array-like of Quantity, str or mix of both) – Bound-bound transition wavelengths or transition labels for the numerator and denominator. If multiple transitions are provided, their contribution functions are summed before taking the ratio. Transition labels must exactly match entries in ion.transitions.label[ion.transitions.is_bound_bound].

  • density (Quantity) – Electron number density.

  • **kwargs – Passed to contribution_function().

Returns:

Quantity – The line ratio with shape (n_temperature, n_density) for independent density arrays or (n_temperature, 1) for couple_density_to_temperature=True. Points where the denominator vanishes are returned as nan.