pyROX.line_by_line.lbl

Classes

LineProfileHelper	Helper class for line profile calculations.
LineByLine	Base class for line-by-line cross-sections.

Module Contents

class pyROX.line_by_line.lbl.LineProfileHelper

Helper class for line profile calculations.

compute_line_strength(T, S_0, E_low, nu_0)

Calculates the line strength for a given temperature.

Parameters:

• T (float) – Temperature in Kelvin.

• S_0 (float) – Line strength at reference temperature.

• E_low (float) – Lower state energy in Joules.

• nu_0 (float) – Transition frequency in s^-1.

Returns:

Line strength in s^-1/(molecule m^-2).

Return type:

float

normalise_wing_cutoff(S, cutoff_distance, gamma_L)

Normalises the line strength to account for wing cutoff.

Parameters:

• S (array) – Line strengths.

• cutoff_distance (float) – Distance for wing cutoff.

• gamma_L (array) – Lorentzian widths.

Returns:

Normalised line strengths.

Return type:

array

pressure_shift(P, T, nu_0, delta=None)

Applies pressure shift to the transition frequency.

Parameters:

• P (float) – Pressure in Pa.

• T (float) – Temperature in Kelvin.

• nu_0 (array) – Transition frequencies in s^-1.

• delta (float, optional) – Pressure shift coefficient.

Returns:

Pressure-shifted frequencies.

Return type:

array

compute_vdw_broadening(P, T, E_low, **kwargs)

Calculates Van der Waals broadening.

Parameters:

• P (float) – Pressure in Pa.

• T (float) – Temperature in Kelvin.

• E_low (float) – Lower state energy in Joules.

• **kwargs – Additional parameters.

Returns:

Van der Waals broadening in s^-1.

Return type:

float

compute_natural_broadening(A)

Calculates natural broadening.

Parameters:

A (float) – Einstein A-coefficient in s^-1.

Returns:

Natural broadening in s^-1.

Return type:

float

compute_doppler_broadening(T, nu_0)

Calculates Doppler broadening.

Parameters:

• T (float) – Temperature in Kelvin.

• nu_0 (float) – Transition frequency in s^-1.

Returns:

Doppler broadening in s^-1.

Return type:

float

compute_lorentz_width(gamma_vdW, gamma_N)

Calculates Lorentzian width.

Parameters:

• gamma_vdW (float) – Van der Waals broadening in s^-1.

• gamma_N (float) – Natural broadening in s^-1.

Returns:

Lorentzian width in s^-1.

Return type:

float

compute_voigt_width(gamma_G, gamma_L)

Calculates Voigt width.

Parameters:

• gamma_G (float) – Gaussian width in s^-1.

• gamma_L (float) – Lorentzian width in s^-1.

Returns:

Voigt width in s^-1.

Return type:

float

_bin_transitions_for_local_cutoff(nu_0)

Bins the transitions to the nearest sub-sampled grid point.

Parameters:

nu_0 (array) – Transition frequencies in s^-1.

Returns:

Indices of transitions per bin.

Return type:

array

apply_local_cutoff(S, nu_0, factor)

Applies local cutoff to line strengths. Retain lines with a certain fraction of cumulative strength.

Parameters:

• S (array) – Line strengths.

• nu_0 (array) – Transition frequencies in s^-1.

• factor (float) – Fraction of cumulative strength to retain.

Returns:

Modified line strengths.

Return type:

array

calculate_line_profiles(nu_0, S, gamma_L, gamma_G, nu_grid, wing_cutoff_distance, delta_nu)

Calculates line profiles in chunks to optimise speed.

Parameters:

• nu_0 (array) – Transition frequencies in s^-1.

• S (array) – Line strengths.

• gamma_L (array) – Lorentzian widths.

• gamma_G (array) – Gaussian widths.

• nu_grid (array) – Wavenumber grid.

• wing_cutoff_distance (float) – Wing cutoff distance in s^-1.

• delta_nu (float) – Wavenumber grid spacing in s^-1.

Returns:

Opacity cross-section on the grid.

Return type:

array

_calculate_line_profiles_one_by_one(nu_0, strength, y, gamma_G, nu_grid, slice_nu_grid)

Calculates line profiles one by one.

Parameters:

• nu_0 (array) – Transition frequencies in s^-1.

• strength (array) – Line strengths.

• y (array) – Complex part of Faddeeva coordinate.

• gamma_G (array) – Gaussian widths.

• nu_grid (array) – Wavenumber grid.

• slice_nu_grid (array) – Slices of the wavenumber grid.

Returns:

Opacity cross-section on the grid.

Return type:

array

_calculate_line_profiles_in_chunks(nu_0, S, gamma_L, gamma_G, nu_grid, wing_cutoff_distance, delta_nu, N_lines_in_chunk=1)

Calculates line profiles in chunks to optimise speed.

Parameters:

• nu_0 (array) – Transition frequencies in s^-1.

• S (array) – Line strengths.

• gamma_L (array) – Lorentzian widths.

• gamma_G (array) – Gaussian widths.

• nu_grid (array) – Wavenumber grid.

• wing_cutoff_distance (float) – Wing cutoff distance in s^-1.

• delta_nu (float) – Wavenumber grid spacing in s^-1.

• N_lines_in_chunk (int) – Number of lines to process in each chunk.

Returns:

Opacity cross-section on the grid.

Return type:

array

_calculate_line_profiles_in_chunks_fixed_delta_nu(nu_0, S, gamma_L, gamma_G, nu_grid, wing_cutoff_distance, delta_nu, N_lines_in_chunk=1)

Calculates line profiles for a fixed wavenumber spacing. This method is more efficient than calculate_line_profiles_in_chunks().

Parameters:

• nu_0 (array) – Transition frequencies in s^-1.

• S (array) – Line strengths.

• gamma_L (array) – Lorentzian widths.

• gamma_G (array) – Gaussian widths.

• nu_grid (array) – Wavenumber grid.

• wing_cutoff_distance (float) – Wing cutoff distance in s^-1.

• delta_nu (float) – Wavenumber grid spacing in s^-1.

• N_lines_in_chunk (int) – Number of lines to process in each chunk.

Returns:

Opacity cross-section on the grid.

Return type:

array

class pyROX.line_by_line.lbl.LineByLine(config, **kwargs)

Bases: pyROX.CrossSections, LineProfileHelper

Base class for line-by-line cross-sections.

_read_configuration_parameters(config)

Reads parameters specific to line-by-line calculations from the configuration.

Parameters:

config (object) – Configuration object containing parameters.

_read_equation_of_state()

Reads the equation of state for the gas mixture.

_read_mass()

Reads the mass of the species from the configuration or database.

_read_pressure_broadening_info()

Reads the pressure broadening parameters from the configuration.

_read_partition_function()

Reads the partition function from the configuration file.

iterate_over_PT_grid(function, progress_bar=True, **kwargs)

Iterates over the pressure-temperature grid and apply a function.

Parameters:

• function (callable) – Function to apply at each grid point.

• progress_bar (bool) – Whether to show a progress bar.

• **kwargs – Additional arguments for the function.

calculate_cross_sections(P, T, nu_0, S_0, E_low, A, delta=None, **kwargs)

Computes the cross-sections for given parameters.

Parameters:

• P (float) – Pressure in Pa.

• T (float) – Temperature in Kelvin.

• nu_0 (array) – Transition frequencies in s^-1.

• S_0 (array) – Line strengths at reference temperature.

• E_low (array) – Lower state energies in Joules.

• A (array) – Einstein A-coefficients in s^-1.

• delta (array, optional) – Pressure shift coefficients.

• **kwargs – Additional arguments.

calculate_temporary_outputs(overwrite=False, save_in_one_file=False, files_range=None, **kwargs)

Calculates temporary outputs for cross-sections.

Parameters:

• overwrite (bool) – Whether to overwrite existing files.

• save_in_one_file (bool) – Whether to save all outputs in one file.

• files_range (tuple, optional) – Range of files to process.

• **kwargs – Additional arguments.

save_combined_outputs(**kwargs)

Saves the merged outputs to a file.

Parameters:

**kwargs – Additional arguments for saving.

plot_combined_outputs(fig=None, ax=None, return_fig_ax=False, cmaps=['coolwarm', 'viridis'], xscale='log', yscale='log', xlim=None, ylim=None, ls='-', lw=0.7, **kwargs)

Plots the merged outputs.

Parameters:

• fig (matplotlib.figure.Figure) – Figure object for plotting.

• ax (matplotlib.axes.Axes) – Axes object for plotting.

• return_fig_ax (bool) – Whether to return the figure and axes.

• cmaps (list) – List of colormaps for plotting.

• xscale (str) – Scale for the x-axis.

• yscale (str) – Scale for the y-axis.

• xlim (tuple, optional) – Limits for the x-axis.

• ylim (tuple, optional) – Limits for the y-axis.

• ls (str) – Line style for plotting.

• **kwargs – Additional arguments for plotting.

convert_to_pRT3(contributor=None, **kwargs)

Converts the cross-sections to petitRADTRANS v3.0 format.

Parameters:

• contributor (str) – Name of the contributor for these data.

• **kwargs – Additional arguments for conversion.

Raises:

• ValueError – If required metadata is missing in the configuration.

• KeyError – If required keys are missing in the metadata.