AHELP for CIAO 4.15 Sherpa
One-dimensional box function.
The model is flat between xlow and xhi (both limits are inclusive), where it is set to the ampl parameter. Outside this range the model is zero.
>>> create_model_component("box1d", "mdl") >>> print(mdl)
Create a component of the box1d model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.xlow thawed 0 -3.40282e+38 3.40282e+38 mdl.xhi thawed 0 -3.40282e+38 3.40282e+38 mdl.ampl thawed 1 -1 1
The attributes for this object are:
|xlow||Coordinate of the lower cut-off.|
|xhi||Coordinate of the upper cut-off.|
|ampl||The amplitude of the box.|
The functional form of the model for points is:
f(x) = ampl if xlow <= x <= xhi = 0 otherwise
and for an integrated grid it is:
f(lo,hi) = ampl if lo >= xlow and hi <= xhi = 0 if hi <= xlow or lo >= xhi = ampl * g where g is the fraction of lo,hi that falls within xlo,xhi
This behavior is different to how the amplitude is handled in other models, such as const1d .
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.