Parameters¶

class gammapy.modeling.Parameters(parameters=None)[source]¶

Bases: collections.abc.Sequence

Parameters container.

List of Parameter objects.
Covariance matrix.

Parameters

parameterslist of Parameter: List of parameters

Attributes Summary

`free_parameters`	List of free parameters
`names`	List of parameter names
`restore_values`	Context manager to restore values.
`types`	Parameter types
`unique_parameters`	Unique parameters (`Parameters`).
`values`	Parameter values (`numpy.ndarray`).

Methods Summary

`autoscale`([method])	Autoscale all parameters.
`check_limits`()	Check parameter limits and emit a warning
`copy`()	A deep copy
`count`(value)
`freeze_all`()	Freeze all parameters
`from_dict`(data)
`from_stack`(parameters_list)	Create `Parameters` by stacking a list of other `Parameters` objects.
`index`(val)	Get position index for a given parameter.
`set_parameter_factors`(factors)	Set factor of all parameters.
`to_dict`()
`to_table`()	Convert parameter attributes to `Table`.

Attributes Documentation

free_parameters¶: List of free parameters

names¶: List of parameter names

restore_values¶

Context manager to restore values.

A copy of the values is made on enter, and those values are restored on exit.

Examples

from gammapy.modeling.models import PowerLawSpectralModel
pwl = PowerLawSpectralModel(index=2)
with pwl.parameters.restore_values:
    pwl.parameters["index"].value = 3
print(pwl.parameters["index"].value)

types¶: Parameter types

unique_parameters¶: Unique parameters (Parameters).

values¶: Parameter values (numpy.ndarray).

Methods Documentation

autoscale(method='scale10')[source]¶

Autoscale all parameters.

See autoscale()

Parameters

method{‘factor1’, ‘scale10’}: Method to apply

check_limits()[source]¶: Check parameter limits and emit a warning

copy()[source]¶: A deep copy

count(value) → integer -- return number of occurrences of value¶

freeze_all()[source]¶: Freeze all parameters

classmethod from_dict(data)[source]¶

classmethod from_stack(parameters_list)[source]¶

Create Parameters by stacking a list of other Parameters objects.

Parameters

parameters_listlist of Parameters: List of Parameters objects

index(val)[source]¶

Get position index for a given parameter.

The input can be a parameter object, parameter name (str) or if a parameter index (int) is passed in, it is simply returned.

set_parameter_factors(factors)[source]¶

Set factor of all parameters.

Used in the optimizer interface.

to_dict()[source]¶

to_table()[source]¶: Convert parameter attributes to Table.