Parameter

class xspec.Parameter(parName, parStrategy)

Model or response parameter class.

Methods

  • untie

Attributes ((*) = get-only)

  • error*
  • frozen
  • index*
  • link
  • name*
  • prior
  • sigma*
  • unit*
  • values
untie()

Remove parameter link (if any)

error

A tuple containing the results of the most recent fit error command performed on the parameter (GET only). The tuple values are: (<error low bound>, <error high bound>, <error status code string>)

frozen

Bool, if True then parameter is frozen.

index

Position of the parameter within the Model object.

(The first parameter has index = 1) Note that this is the same value that would be used to obtain a Parameter object from its Model, ie: par = mod(<index>) (GET only).

Parameter link expression string (empty if not linked).

name

Name of Parameter (GET only).

prior

A tuple containing the settings for the prior used when Bayesian inference is turned on.

Get: Returns a tuple containing:
(<priorType>, <optional hyperparameters>)
Set with:

string: <priorType>

or tuple: (<priorType>, <optional hyperparameters>)

Valid priorTypes are 'cons', 'exp', 'jeffreys', 'gauss'. Hyperparameters should be entered as floats.

sigma

The Parameter fit sigma (-1.0 when not applicable) (GET only).

unit

An optional string for the parameter's units (GET only).

values

List of value floats [val,delta,min,bot,top,max].

This may be set with:

string: x.values = "3.2,,,,1e2, 1e3"

single float: x.values = 4.1 (sets 'val' only)

tuple: x.values = 8.2,.02, -10.

list: x.values = [8.2,.02, -10.]

Note that Tuple and List input do not allow the use of consecutive commas for argument spacing.