BaseParam

class sherpa.astro.io.xstable.BaseParam(name: str, initial: float, delta: float, hardmin: float, hardmax: float, softmin: float | None = None, softmax: float | None = None)[source] [edit on github]

Bases: object

Represent a parameter.

The absolute DELTA value is used by XSPEC but ignored by Sherpa. The sign of DELTA is used (by both Sherpa and XSPEC) to decide if the parameter should be frozen (DELTA is negative) or not by default.

Attributes Summary

`softmax`	The "soft" maximum.
`softmin`	The "soft" minimum.
`name`	The parameter name.
`initial`	The default value for the parameter.
`delta`	The delta value for fitting.
`hardmin`	The minimum value for the parameter.
`hardmax`	The maximum value for the parameter.

Attributes Documentation

softmax: float | None = None: The “soft” maximum. Defaults to hardmax if not given.

softmin: float | None = None: The “soft” minimum. Defaults to hardmin if not given..

name: str

The parameter name.

This must be unique and ideally a valid attribute name in Python, although the latter is not enforced.

initial: float: The default value for the parameter.

delta: float

The delta value for fitting.

If negative then the parameter defaults to being frozen. Sherpa does not use this value (other than checking the sign) but XSPEC does.

hardmin: float: The minimum value for the parameter.

hardmax: float: The maximum value for the parameter.