One-dimensional power-law function.
It is assumed that the independent axis is positive at all points.
>>> create_model_component("powlaw1d", "mdl") >>> print(mdl)
Create a component of the powlaw1d model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.gamma thawed 1 -10 10 mdl.ref frozen 1 -3.40282e+38 3.40282e+38 mdl.ampl thawed 1 0 3.40282e+38
The attributes for this object are:
The photon index of the power law.
As the reference point is degenerate with the amplitude, the alwaysfrozen attribute of the reference point is set so that it can not be varied during a fit.
The amplitude of the model.
The functional form of the model for points is:
f(x) = ampl * (x / ref)^(-gamma)
and for an integrated grid it is the integral of this over the bin.
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.