AbsorptionVoigt¶
-
class
sherpa.astro.optical.
AbsorptionVoigt
(name='absorptionvoigt')[source] [edit on github]¶ Bases:
sherpa.models.model.RegriddableModel1D
Voigt function for modeling absorption (equivalent width).
This model uses an
AbsorptionGaussian
component to model the core of the profile and anAbsorptionLorentz
component to model the wings of the absorption feature. This model is intended to be used to modify another model (e.g. by multiplying the two together). It is for use when the independent axis is in Angstroms.-
center
¶ The center of the profile, in Angstroms.
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ew
¶ The equivalent width of the profile. The ewidth parameter of the Gaussian and Lorentz sub-components is set to half this value.
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fwhm
¶ The full-width half-maximum of the model in km/s.
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lg
¶ The fwhm parameters of the Gaussian and Lorentz components are set based on the
fwhm
andlg
values: the Gaussian component has its fwhm parameter set equal tofwhm
, and the Lorentz component has its fwhm parameter set tolg * fwhm
.
Notes
The Voigt function is approximated by the sum of a Gaussian and a Lorentzian profile ([1]), which works best when the ratio between the FWHM of the Gaussian and Lorentzian sub-components is near unity. The flux value is always kept evenly divided in between each sub-component. The FWHM of each sub-component is related to that of the other sub-component via the lg parameter.
References
[1] - Lang, Astrophysical Formulae, 1980, 2nd ed., page 220
Attributes Summary
thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars
Methods Summary
apply
(outer, *otherargs, **otherkwargs)calc
(p, x[, xhi])Evaluate the model on a grid. get_center
()guess
(dep, *args, **kwargs)Set an initial guess for the parameter values. regrid
(*arrays)reset
()set_center
(*args, **kwargs)startup
()Called before a model may be evaluated multiple times. teardown
()Called after a model may be evaluated multiple times. Attributes Documentation
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thawedparhardmaxes
¶
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thawedparhardmins
¶
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thawedparmaxes
¶
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thawedparmins
¶
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thawedpars
¶
Methods Documentation
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apply
(outer, *otherargs, **otherkwargs) [edit on github]¶
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calc
(p, x, xhi=None, **kwargs)[source] [edit on github]¶ Evaluate the model on a grid.
Parameters: - p (sequence of numbers) – The parameter values to use. The order matches the
pars
field. - *args – The model grid. The values can be scalar or arrays, and the number depends on the dimensionality of the model and whether it is being evaluated over an integrated grid or at a point (or points).
- p (sequence of numbers) – The parameter values to use. The order matches the
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get_center
() [edit on github]¶
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guess
(dep, *args, **kwargs) [edit on github]¶ Set an initial guess for the parameter values.
Attempt to set the parameter values, and ranges, for the model to match the data values. This is intended as a rough guess, so it is expected that the model is only evaluated a small number of times, if at all.
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regrid
(*arrays) [edit on github]¶
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reset
() [edit on github]¶
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set_center
(*args, **kwargs) [edit on github]¶
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startup
() [edit on github]¶ Called before a model may be evaluated multiple times.
See also
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teardown
() [edit on github]¶ Called after a model may be evaluated multiple times.
See also
setup()
-