LogEmission¶
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class
sherpa.astro.optical.
LogEmission
(name='logemission')[source]¶ Bases:
sherpa.models.model.ArithmeticModel
Gaussian function for modeling emission (log of fwhm).
It is for use when the independent axis is in Angstroms.
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fwhm
¶ The full-width half-maximum of the model in km/s.
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pos
¶ The center of the gaussian, in Angstroms.
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flux
¶ The normalisation of the gaussian.
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skew
¶ The skew of the gaussian.
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limit
¶ This is a hidden parameter and is unused by the model.
See also
EmissionGaussian
,EmissionLorentz
,EmissionVoigt
,LogAbsorption
Notes
The functional form of the model for points is:
f(x) = fmax * (x / pos)^arg if x <= pos fmax * (x / pos)^(-alpha) otherwise arg = log(2) / log(1 + 0.5 * fwhm / c) arg1 = log(2) / log(1 + 0.5 * skew * fwhm / c) alpha = arg if skew == 1 = arg1 otherwise fmax = (arg - 1) * flux / (2 * pos) if skew == 1 = (arg - 1) * flux / (pos * (1 + (arg - 1) / (arg1 - 1))) otherwise c = 2.9979e5
and for integrated data sets the low-edge of the grid is used.
Attributes Summary
thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars
Methods Summary
apply
(outer, \*otherargs, \*\*otherkwargs)calc
(p, x[, xhi])get_center
()guess
(dep, \*args, \*\*kwargs)Set an initial guess for the parameter values. reset
()set_center
(\*args, \*\*kwargs)startup
()teardown
()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)¶
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get_center
()¶
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guess
(dep, *args, **kwargs)¶ 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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reset
()¶
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set_center
(*args, **kwargs)¶
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startup
()¶
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teardown
()¶
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