pint.models.parameter.prefixParameter

class pint.models.parameter.prefixParameter(parameter_type='float', name=None, value=None, units=None, unit_template=None, description=None, description_template=None, uncertainty=None, frozen=True, continuous=True, prefix_aliases=None, long_double=False, unit_scale=False, scale_factor=None, scale_threshold=None, time_scale='utc', **kwargs)

Bases: object

Families of parameters identified by a prefix like DMX_0123.

Creating a prefixParameter is like creating a normal parameter, except that the name should be in the format of prefix and index. For example, DMX_0001 or F22. Appropriate units will be inferred.

To create a prefix parameter with the same prefix but different index, just use the pint.models.parameter.prefixParameter.new_param() method. It will return a new prefixParameter with the same setup but a new index. Some units and descriptions will be changed once the index has been changed. The new parameter will not inherit the frozen status of its parent by default. In order to get the right units and description, .unit_template and .description_template should be provided. If not the new prefix parameter will use the same units and description with the old one. A typical description and units template is like:

>>> description_template = lambda x: 'This is the description of parameter %d'%x
>>> unit_template = lambda x: 'second^%d'%x

Although it is best to avoid using lambda functions

Parameters:

• parameter_type (str, optional) – Example parameter class template for quantity and value setter

• name (str optional) – The name of the parameter. It has to be in the format of prefix + index.

• value – Initial parameter value

• units (str, optional) – Units that the value is expressed in

• unit_template (callable) – The unit template for prefixed parameter

• description (str, optional) – Description for the parameter

• description_template (callable) – Description template for prefixed parameters

• prefix_aliases (list of str, optional) – Alias for the prefix

• frozen (bool, optional) – A flag specifying whether “fitters” should adjust the value of this parameter or leave it fixed.

• continuous (bool) – Whether derivatives with respect to this parameter make sense.

• parameter_type – Example parameter class template for quantity and value setter

• long_double (bool, optional) – Set float type quantity and value in numpy long doubles.

• time_scale (str, optional) – Time scale for MJDParameter class.

Methods

as_latex()
as_parfile_line([format])
as_ufloat([units])	Return the parameter as a uncertainties.ufloat
from_parfile_line(line)
help_line()
name_matches(name)
new_param(index[, inheritfrozen])	Get one prefix parameter with the same type.
prefix_matches(prefix)
prior_pdf([value, logpdf])
str_quantity(quan)

Attributes

aliases
continuous
description
frozen
prior
quantity
repeatable
special_arg
uncertainty
uncertainty_value
units
use_alias
value

new_param(index, inheritfrozen=False)

Get one prefix parameter with the same type.

Parameters:

• index (int) – index of prefixed parameter.

• inheritfrozen (bool, optional) – whether or not the parameter should inherit the “frozen” status of the base parameter

Return type:

A prefixed parameter with the same type of instance.

as_ufloat(units=None)

Return the parameter as a uncertainties.ufloat

Will cast to the specified units, or the default If the uncertainty is not set will be returned as 0

Parameters:

units (astropy.units.core.Unit, optional) – Units to cast the value

Return type:

uncertainties.ufloat