pint.models.parameter.floatParameter

class pint.models.parameter.floatParameter(name=None, value=None, units=None, description=None, uncertainty=None, frozen=True, aliases=None, continuous=True, long_double=False, unit_scale=False, scale_factor=None, scale_threshold=None, **kwargs)[source]

Bases: Parameter

Parameter with float or long double value.

.quantity stores current parameter value and its unit in an Quantity. Upon storage in .quantity the input is converted to self.units.

Parameters:

name (str) – The name of the parameter.
value (number, str, or astropy.units.Quantity) – The input parameter float value.
units (str or astropy.units.Quantity) – Parameter default unit. Parameter .value and .uncertainty_value attribute will associate with the default units. If unit is dimensionless, use “’’” as its unit.
description (str, optional) – A short description of what this parameter means.
uncertainty (number) – Current uncertainty of the value.
frozen (bool, optional) – A flag specifying whether “fitters” should adjust the value of this parameter or leave it fixed.
aliases (list, optional) – An optional list of strings specifying alternate names that can also be accepted for this parameter.
continuous (bool, optional, default True) – A flag specifying whether phase derivatives with respect to this parameter exist.
long_double (bool, optional, default False) – A flag specifying whether value is float or long double.

Example

>>> from parameter import floatParameter
>>> test = floatParameter(name='test1', value=100.0, units='second')
>>> print(test)
test1 (s) 100.0

Methods

`add_alias`(alias)	Add a name to the list of aliases for this parameter.
`as_latex`()
`as_parfile_line`([format])	Return a parfile line giving the current state of the parameter.
`as_ufloat`([units])	Return the parameter as a `uncertainties.ufloat`
`from_parfile_line`(line)	Parse a parfile line into the current state of the parameter.
`from_ufloat`(value[, units])	Set the parameter from the value of a `uncertainties.ufloat`
`help_line`()	Return a help line containing parameter name, description and units.
`name_matches`(name)	Whether or not the parameter name matches the provided name
`prior_pdf`([value, logpdf])	Return the prior probability density.
`set`(value)	Deprecated - just assign to .value.
`str_quantity`(quan)	Quantity as a string (for floating-point values).
`value_as_latex`()

Attributes

`long_double`	Whether the parameter has long double precision.
`prior`	prior distribution for this parameter.
`quantity`	Value including units (if appropriate).
`repeatable`
`uncertainty`	Parameter uncertainty value with units.
`uncertainty_value`	Return a pure value from .uncertainty.
`unit_scale`	If True, the parameter can automatically scale some values upon assignment.
`units`	Units associated with this parameter.
`value`	Return the value (without units) of a parameter.

property long_double: Whether the parameter has long double precision.

property unit_scale: If True, the parameter can automatically scale some values upon assignment.

str_quantity(quan)[source]: Quantity as a string (for floating-point values).

as_ufloat(units=None)[source]

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

Notes

Currently ufloat does not support double precision values, so some precision may be lost.

from_ufloat(value, units=None)[source]

Set the parameter from the value of a uncertainties.ufloat

Will cast to the specified units, or the default If the uncertainty is 0 it will be set to None

Parameters:

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

add_alias(alias): Add a name to the list of aliases for this parameter.

as_parfile_line(format='pint')

Return a parfile line giving the current state of the parameter.

Parameters:: format (str, optional) – Parfile output format. PINT outputs in ‘tempo’, ‘tempo2’ and ‘pint’ formats. The default format is pint.
Return type:: str

Notes

Format differences between tempo, tempo2, and pint at [1]

from_parfile_line(line)

Parse a parfile line into the current state of the parameter.

Returns True if line was successfully parsed, False otherwise.

Note

The accepted formats:

NAME value
NAME value fit_flag
NAME value fit_flag uncertainty
NAME value uncertainty

help_line(): Return a help line containing parameter name, description and units.

name_matches(name): Whether or not the parameter name matches the provided name

property prior

prior distribution for this parameter.

This should be a Prior object describing the prior distribution of the quantity, for use in Bayesian fitting.

prior_pdf(value=None, logpdf=False)

Return the prior probability density.

Evaluated at the current value of the parameter, or at a proposed value.

Parameters:

value (array-like or float, optional) – Where to evaluate the priors; should be a unitless number. If not provided the prior is evaluated at self.value.
logpdf (bool) – If True, return the logarithm of the PDF instead of the PDF; this can help with densities too small to represent in floating-point.

property quantity: Value including units (if appropriate).

set(value): Deprecated - just assign to .value.

property uncertainty: Parameter uncertainty value with units.

property uncertainty_value

Return a pure value from .uncertainty.

This will be interpreted as having units self.units.

property units

Units associated with this parameter.

Should be a astropy.units.Unit object, or None if never set.

property value

Return the value (without units) of a parameter.

This value is assumed to be in units of self.units. Upon setting, a a Quantity can be provided, which will be converted to self.units.