AbsorptionLorentz¶

class sherpa.astro.optical.AbsorptionLorentz(name='absorptionlorentz')[source]¶

Bases: sherpa.models.model.ArithmeticModel

Lorentz function for modeling absorption (equivalent width).

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.

fwhm¶: The full-width half-maximum of the model in km/s.

pos¶: The center of the lorentzian, in Angstroms.

ewidth¶: The equivalent width of the model.

Notes

The functional form of the model for points is:

f(x) = 1 - ewidth * c / (1.571 * fwhm * pos * l(x))

l(x) = 1 + 4 * ((1 / x - 1 / pos) * pos * c / fwhm)^2

c = speed of light in km/s

and for integrated data sets the low-edge of the grid is used.

The speed of light can be found by inspecting the module variable sherpa.astro.optical.c_km.

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

thawedparhardmaxes¶

thawedparhardmins¶

thawedparmaxes¶

thawedparmins¶

thawedpars¶

Methods Documentation

apply(outer, *otherargs, **otherkwargs)¶

calc(p, x, xhi=None, **kwargs)[source]¶

get_center()¶

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.

reset()¶

set_center(*args, **kwargs)¶

startup()¶

teardown()¶