pychell API reference

Forward Models

Model Components

class pychell.rvs.model_components.BasicFringingModel(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.EmpiricalMult

A basic Fabry-Perot cavity model.

class pychell.rvs.model_components.EmpiricalMult(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.MultModelComponent

Base class for an empirically derived multiplicative (or log-additive) spectral component (i.e., based purely on parameters, no templates involved).

class pychell.rvs.model_components.FullBlazeModel(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.EmpiricalMult

A full blaze transmission model. A sinc^(d) and an additive cubic spline correction are used.

n_splines

The number of wavelength splines.

Type:int

n_delay_splines

The number of iterations to delay the splines.

Type:int

splines_enabled

Whether or not the splines are enabled.

Type:bool

blaze_wave_estimate

The estimate of the blaze wavelegnth. If not provided, defaults to the average of the wavelength grid provided in the build method.

Type:bool

spline_set_points

The location of the spline knots.

Type:np.ndarray

class pychell.rvs.model_components.GasCellModel(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.TemplateMult

A gas cell model which is consistent across orders.

class pychell.rvs.model_components.GasCellModelOrderDependent(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.TemplateMult

A gas cell model which is not consistent across orders.

class pychell.rvs.model_components.LSFHermiteModel(blueprint, dl, nx_model, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.LSFModel

A Hermite Gaussin LSF model. The model is a sum of Gaussians of constant width but coefficients to enforce orthonormality.

hermdeg

The degree of the hermite model

Type:int

class pychell.rvs.model_components.LSFModel(blueprint, dl, nx_model, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.SpectralComponent

A base class for an LSF (line spread function) model.

compress

The number of lsf points is equal to the number of model pix / compress.

Type:int

dl

The step size of the high resolution fidicual wavelength grid the model is convolved on. Must be evenly spaced.

Type:float

nx_model

The number of model pixels in the high resolution fidicual wavelength grid.

Type:float

nx

The number of points in the lsf grid.

Type:int

x

The lsf grid.

Type:np.ndarray

class pychell.rvs.model_components.LSFModelKnown(blueprint, dl, nx_model, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.LSFModel

A container for a known LSF. In reality this can and probably should not be used and avoided.

class pychell.rvs.model_components.MultModelComponent(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.SpectralComponent

Base class for a multiplicative (or log-additive) spectral component.

wave_bounds

The approximate left and right wavelength endpoints of the considered data.

Type:list

flux_logspace

Whether or not this model is generated in logspace. It is recommended the log is accounted for in the corresponding build_full method, not here (for now).

Type:bool

base_par_names

The base parameter names (constant) for this model.

Type:list

par_names

The full parameter names for this specific run.

Type:list

class pychell.rvs.model_components.ResidualBlazeModel(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.EmpiricalMult

Residual blaze transmission model, ideally used after a flat field correction. A quadratic and an additive cubic spline correction are used.

n_splines

The number of wavelength splines.

Type:int

n_delay_splines

The number of iterations to delay the splines.

Type:int

splines_enabled

Whether or not the splines are enabled.

Type:bool

blaze_wave_estimate

The estimate of the blaze wavelegnth. If not provided, defaults to the average of the wavelength grid provided in the build method.

Type:bool

spline_set_points

The location of the spline knots.

Type:np.ndarray

class pychell.rvs.model_components.SpectralComponent(blueprint, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: object

Base class for a general spectral component model.

blueprint

The blueprints to construct this component from.

Type:dict

order_num

The image order number.

Type:int

enabled

Whether or not this model is enabled.

Type:bool

name

The name of this model, may be anything.

Type:str

Base initialization for a model component.

Parameters:

• blueprint (dict) – The blueprints to construct this component from.
• order_num (int) – The image order number.

class pychell.rvs.model_components.StarModel(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.TemplateMult

A star model which may or may not have started from a synthet template.

class pychell.rvs.model_components.StarModelOrderDependent(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.SpectralComponent

A star model which is order dependent. For now this is only used for Minerva-Australis.

class pychell.rvs.model_components.TelluricModelTAPAS(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.TemplateMult

A telluric model based on Templates obtained from TAPAS. These templates should be pre-fetched from TAPAS and specific to the observatory. Each species has a unique depth, but the model is locked to a common Doppler shift.

species

The names (strings) of the telluric species.

Type:list

n_species

The number of telluric species.

Type:int

species_enabled

A dictionary with species as keys, and boolean values for items (True=enabled, False=disabled)

Type:bool

species_input_files

A list of input files (strings) for the individual species.

Type:list

class pychell.rvs.model_components.TemplateMult(blueprint, wave_bounds, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.MultModelComponent

A base class for a template based multiplicative model.

input_file

If provided, stores the full path + filename of the input file.

Type:str

class pychell.rvs.model_components.WaveModelKnown(blueprint, wave_bounds, pix_bounds, nx, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.WavelengthSolutionModel

Class for a wavelength solution which starts from some pre-derived solution (say a ThAr lamp).

n_splines

The number of wavelength splines.

Type:int

n_delay_splines

The number of iterations to delay the splines.

Type:int

splines_enabled

Whether or not the splines are enabled.

Type:bool

spline_pixel_set_points

The location of the spline knots.

Type:np.ndarray

class pychell.rvs.model_components.WaveSolModelFull(blueprint, wave_bounds, pix_bounds, nx, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.WavelengthSolutionModel

Class for a full wavelength solution. A “base” solution is provided by a quadratic through set points, and a cubic spline offset is added on to capture any local perturbations.

n_splines

The number of wavelength splines.

Type:int

n_delay_splines

The number of iterations to delay the splines.

Type:int

splines_enabled

Whether or not the splines are enabled.

Type:bool

base_pixel_set_points

The three pixel points to use as set points in the quadratic.

Type:np.ndarray

base_wave_zero_points

Estimates of the corresonding zero points of base_pixel_set_points.

Type:np.ndarray

spline_pixel_set_points

The location of the spline knots.

Type:np.ndarray

class pychell.rvs.model_components.WavelengthSolutionModel(blueprint, wave_bounds, pix_bounds, nx, order_num=None, wave_logspace=False, flux_logspace=False)

Bases: pychell.rvs.model_components.SpectralComponent

A base class for a wavelength solution (i.e., conversion from pixels to wavelength).

pix_bounds

The left and right pixel bounds which correspond to wave_bounds.

Type:list

nx

The total number of data pixels.

Type:int