AbsorptionEdge¶

class sherpa.astro.optical.AbsorptionEdge(name='absorptionedge')[source]¶

Bases: sherpa.models.model.ArithmeticModel

Optical model of an absorption edge.

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 wavelength units (e.g. Angstrom).

egdew¶: The location of the edge. Above this value the model is set to 1.

tau¶: The optical depth of the edge.

index¶: The exponent used for the relative distance from the edge. It is a hidden parameter, with a value fixed at 3.

Notes

The functional form of the model for points is:

f(x) = exp(-tau * (x / edgew)^index)   for x <= edgew

     = 1                               otherwise

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

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()¶