API

An application programming interface (API) defines a set of routines to provides access to functions of a software without using a user interface. FitELP (Fit Emission-Line Profiles) has a few entry points into the API. Following we show the more important classes and methods.

Basic Classes and Methods

Plotting Methods

Latex Tables Methods

The full documentation can be found below.

Full Documentation

class fitelp.line_profile_info.RegionParameters(region_name, blue_spec_file, red_spec_file, blue_spec_error_file, red_spec_error_file, scale_flux, center_list, sigma_list, lin_slope, lin_int, num_comps, component_labels, component_colors, sigma_instr_blue, sigma_inst_red, distance, em_lines_for_avg_vel_calc, plotting_x_range=None, plot_residuals=True, show_systemic_velocity=False, systemic_velocity=None)[source]

List information about a region containing multiple emission lines

region_name : str
Name of object. Do not use underscores in name, as this may affect latex compiling.
blue_spec_file : str
FITS file path of the blue spectrum
red_spec_file : str
FITS file path of the red spectrum
blue_spec_error_file : str
FITS file path of the blue spectrum error
red_spec_error_file : str
FITS file path of the red spectrum error
scale_flux : float
scales the fluxes from the files by this factor during fitting.
center_list : dict
The center values of the gaussian components for the low-ionization (e.g H-Alpha) and high-ionization (e.g [OIII]5007) zones of each gaussian. These values will depend on the type of fit, if it is in velocity or wavelength. E.g. centerList = {‘low’: [3918.56, 3969.72, 3978.93], ‘high’: [3923.50, 3970.63, 3984.13]}
sigma_list : dict
The sigma values of the gaussian components for the low-ionization (e.g H-Alpha) and high-ionization (e.g [OIII]5007) zones of each gaussian. These values will depend on the type of fit, if it is in velocity or wavelength. E.g. sigmaList = {‘low’: [17.123, 13.868, 45.207],’high’: [15.740, 12.875, 43.667]}
lin_slope : dict
The linear slope values representing the continuum for the low-ionization (e.g H-Alpha) and high-ionization (e.g [OIII]5007) zones. This value will depend on the type of fit, if it is in velocity or wavelength. E.g. lin_slope = {‘low’: -5.2237e-08, ‘high’: -2.8976e-07}
lin_int : dict
The linear intercept values representing the continuum the low-ionization (e.g H-Alpha) and high-ionization (e.g [OIII]5007) zones. This value will depend on the type of fit, if it is in velocity or wavelength. E.g. lin_int = {‘low’: 0.00139680, ‘high’: 0.00254310}
num_comps : dict
The number of gaussian components for the low-ionization (e.g H-Alpha) and high-ionization (e.g [OIII]5007) zones. This should be the length of the lists of the center and sigma of each of the gaussian components E.g. num_comps = {‘low’: 3, ‘high’: 3} or num_comps = {‘low’: 3, ‘high’: 5}
component_labels : list
Labels for each of the gaussian components in the order that they are presented in all other lists. E.g. component_labels = [‘Narrow 1’, ‘Narrow 2’, ‘Broad’]
component_colors : list
Colour to plot each of the gaussian components in the order that they appear in component_labels. E.g. componentColours = [‘r’, ‘c’, ‘g’]
sigma_instr_blue : float
The instrumental profile (σi) in the blue-arm of the spectrograph. It is well approximated by a single Gaussian function.
sigma_inst_red : float
The instrumental profile (σi) in the red-arm of the spectrograph. It is well approximated by a single Gaussian function.
distance : float
The distance to the region in centimetres (same units that distance appears in the input flux)
em_lines_for_avg_vel_calc : list
The emission lines to use to calculate the average velocity. E.g. emLinesForAvgVelCalc = [‘H-Alpha’, ‘H-Beta’, ‘OIII-5007A’, ‘NII-6584A’, ‘SII-6717A’]
plotting_x_range: list or None
The wavelength (or velocity) range to plot each of the emission line gaussians. E.g. plotting_x_range = [3600, 4400]
plot_residuals : bool
Whether to plot the residuals of the fit in an extra panel below the gaussian Default is True.
show_systemic_velocity : bool
Assumed False if it is not defined. If True, the xAxis is plotted as the measured velocity minus the systemicVelocity: (velocity - systemicVelocity)
systemic_velocity : float or None
Required if show_systemic_velocity is True.
add_em_line(name, plot_color, order, filter, min_idx, max_idx, rest_wavelength, amp_list, zone, sigma_tsquared, comp_limits, copy_from, num_comps=None)[source]

Emission line info

name : str
Name of emission line. E.g. ‘H-Alpha’ or NII-6584A. This name must be in the appropriate format. This name must be in the appropriate format (see ALL_IONS list in constants.py).
plot_color : str
The color that this emission line should appear in each of the plots.
order : int
The order that this emission line appears in the Echelle FITS files or 1 for Longslit FIT file.
filter : str
‘red’ or ‘blue’. Indicating the red-arm or blue-arm of the spectrograph where the emission line appears in the spectrum.
min_idx : int
Minimum index of the region in the spectra that includes this emission line.
max_idx : int
Maximum index of the region in the spectra that includes this emission line.
rest_wavelength : float
The rest wavelength of this emission line.
num_comps : int (optional)
The number of Gaussian components to fit the emission line. This overrides the num_comps set in RegionParameters for this emission line only.
amp_list: list or float
The list of amplitudes for each of the components that are included. This must be a list with the same number of elements as ‘num_comps’. If this is a float, then the amplitudes from the emission line listed in the copy_from parameter will be used and divided by this value.
zone : str
‘low’ or ‘high’ ionization zone. Two-ionization-zone scheme is assumed: the low-ionization zone where the hydrogen recombination lines and [OI], [OII], [NII], [SII] forbidden lines are emitted, and the high-ionization zone where the helium recombination lines and [OIII], [SIII], [ArIII], [NeIII] forbidden lines are emitted (Hägele et al., 2012).
sigma_tsquared : float
squared of the random thermal motion (σt). In the example, the thermal contribution was derived from the Boltzmann’s equation, assuming a typical kinetic temperature T≃10^4K and the atomic mass of the corresponding element.
comp_limits : dict
The limits in ‘compLimits’ can be in the following forms: - a list indicating the limits for each component - a single number indicating the percentage limits for ALL components - a tuple (minValue, maxValue) indicating the min and max not in a percentage - inf: indicating that the component can vary - False: indicating that the value is fixed
copy_from : str or None or list
The name of the emission line to copy from. If None, it will not copy any information. If it is a list, it must be the length of the number of components you have (as defined in num_comps in RegionParameters). Each element of the list must be a string indicating which emission line to copy for each component.
class fitelp.kinematics_calculations.RegionCalculations(rp, xAxis='vel', initVals='vel')[source]

Compute kinematics of a region.

rp : RegionParameters object
An instance of the RegionParameters class.
xAxis : str
Plots the x axis in velocity space if xAxis=’vel’ and in wavelength space if xAxis=’wave’. Default is ‘vel’.
initVals : str
Interprets the initial values from all the parameters (i.e. center, sigma, amplitude) as velocities if initVals=’vel’ or as wavelengths if initVals=’wave’
fitelp.bpt_plotting.bpt_plot(rpList, rpBptPoints, globalOnly=False, plot_type='NII')[source]
fitelp.fit_line_profiles.plot_profiles(lineNames, rp, nameForComps='', title='', sortedIndex=None, plotAllComps=False, xAxis='vel', logscale=False, ymin=None)[source]
fitelp.make_latex_tables.average_velocities_table_to_latex(rpList, directory=None, paperSize='a4', orientation='portrait', longTable=False)[source]
fitelp.make_latex_tables.halpha_regions_table_to_latex(regionInfoArray, directory=None, paperSize='a4', orientation='portrait', longTable=False)[source]
fitelp.make_latex_tables.comp_table_to_latex(componentArray, rp, paperSize='a4', orientation='portrait', longTable=True, xAxisUnits='vel', scaleFlux=100000000000000.0)[source]