Beta1D

class sherpa.astro.models.Beta1D(name='beta1d')[source] [edit on github]

Bases: sherpa.models.model.RegriddableModel1D

One-dimensional beta model function.

The beta model is a Lorentz model with a varying power law.

r0

The core radius.

beta

This parameter controls the slope of the profile at large radii.

xpos

The reference point of the profile. This is frozen by default.

ampl

The amplitude refers to the maximum value of the model, at x = xpos.

Notes

The functional form of the model for points is:

f(x) = ampl * (1 + ((x - xpos) / r0)^2)^(0.5 - 3 * beta)

The grid version is evaluated by numerically intgerating the function over each bin using a non-adaptive Gauss-Kronrod scheme suited for smooth functions [1], falling over to a simple trapezoid scheme if this fails.

References

[1]https://www.gnu.org/software/gsl/manual/html_node/QNG-non_002dadaptive-Gauss_002dKronrod-integration.html

Attributes Summary

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Summary

apply(outer, *otherargs, **otherkwargs)
calc(pars, xlo, *args, **kwargs)
get_center()
guess(dep, *args, **kwargs) Set an initial guess for the parameter values.
regrid(*arrays)
reset()
set_center(xpos, *args, **kwargs)
startup() Called before a model may be evaluated multiple times.
teardown() Called after a model may be evaluated multiple times.

Attributes Documentation

thawedparhardmaxes
thawedparhardmins
thawedparmaxes
thawedparmins
thawedpars

Methods Documentation

apply(outer, *otherargs, **otherkwargs) [edit on github]
calc(pars, xlo, *args, **kwargs) [edit on github]
get_center()[source] [edit on github]
guess(dep, *args, **kwargs)[source] [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.

regrid(*arrays) [edit on github]
reset() [edit on github]
set_center(xpos, *args, **kwargs)[source] [edit on github]
startup() [edit on github]

Called before a model may be evaluated multiple times.

See also

teardown()

teardown() [edit on github]

Called after a model may be evaluated multiple times.

See also

setup()