pint.models.cmwavex.CMWaveX

class pint.models.cmwavex.CMWaveX

Bases: Chromatic

Fourier representation of chromatic variations.

Used for decomposition of chromatic noise into a series of sine/cosine components with the amplitudes as fitted parameters.

Parameters supported:

Name / Aliases	Description	Kind
CMWXEPOCH	Reference epoch for Fourier representation of chromatic noise	d
CMWXFREQ_{number}	Component frequency for Fourier representation of chromatic noise	1 / d
CMWXSIN_{number}	Sine amplitudes for Fourier representation of chromatic noise	pc / (MHz2 cm3)
CMWXCOS_{number}	Cosine amplitudes for Fourier representation of chromatic noise	pc / (MHz2 cm3)

To set up a CMWaveX model, users can use the pint.utils function cmwavex_setup() with either a list of frequencies or a choice of harmonics of a base frequency determined by 2 * pi /Timespan

Methods

add_cmwavex_component(cmwxfreq[, index, ...])	Add CMWaveX component
add_cmwavex_components(cmwxfreqs[, indices, ...])	Add CMWaveX components with specified base frequencies
add_param(param[, deriv_func, setup])	Add a parameter to the Component.
chromatic_time_delay(cm, alpha, freq)	Return the chromatic time delay for a set of frequencies.
chromatic_type_delay(toas)
cm_value(toas)	Compute modeled CM value at given TOAs.
cmwavex_cm(toas)
cmwavex_delay(toas[, acc_delay])
d_cm_d_CMWXCOS(toas, param[, acc_delay])
d_cm_d_CMWXSIN(toas, param[, acc_delay])
d_delay_d_cmparam(toas, param_name[, acc_delay])	Derivative of delay wrt to CM parameter.
get_indices()	Returns an array of intergers corresponding to CMWaveX component parameters using CMWXFREQs
get_params_of_type(param_type)	Get all the parameters in timing model for one specific Parameter subtype.
get_prefix_mapping_component(prefix)	Get the index mapping for the prefix parameters.
is_in_parfile(para_dict)	Check if this subclass included in parfile.
match_param_aliases(alias)	Return the parameter corresponding to this alias.
param_help()	Print help lines for all available parameters in model.
print_par([format])	param format: Parfile output format. PINT outputs the 'tempo', 'tempo2' and 'pint'
register_cm_deriv_funcs(func, param)	Register the derivative function in to the deriv_func dictionaries.
register_deriv_funcs(func, param)	Register the derivative function in to the deriv_func dictionaries.
remove_cmwavex_component(index)	Remove all CMWaveX components associated with a given index or list of indices
remove_param(param)	Remove a parameter from the Component.
set_special_params(spcl_params)
setup()	Finalize construction loaded values.
validate()	Validate loaded values.
validate_toas(toas)	Check that this model component has TOAs where needed.

Attributes

aliases_map	Return all the aliases and map to the PINT parameter name.
category
component_types
free_params_component	Return the free parameters in the component.
param_prefixs
register

add_cmwavex_component(cmwxfreq, index=None, cmwxsin=0, cmwxcos=0, frozen=True)

Add CMWaveX component

Parameters:

• cmwxfreq (float or astropy.quantity.Quantity) – Base frequency for CMWaveX component

• index (int, None) – Interger label for CMWaveX component. If None, will increment largest used index by 1.

• cmwxsin (float or astropy.quantity.Quantity) – Sine amplitude for CMWaveX component

• cmwxcos (float or astropy.quantity.Quantity) – Cosine amplitude for CMWaveX component

• frozen (iterable of bool or bool) – Indicates whether CMWaveX parameters will be fit

Returns:

index – Index that has been assigned to new CMWaveX component

Return type:

int

add_cmwavex_components(cmwxfreqs, indices=None, cmwxsins=0, cmwxcoses=0, frozens=True)

Add CMWaveX components with specified base frequencies

Parameters:

• cmwxfreqs (iterable of float or astropy.quantity.Quantity) – Base frequencies for CMWaveX components

• indices (iterable of int, None) – Interger labels for CMWaveX components. If None, will increment largest used index by 1.

• cmwxsins (iterable of float or astropy.quantity.Quantity) – Sine amplitudes for CMWaveX components

• cmwxcoses (iterable of float or astropy.quantity.Quantity) – Cosine amplitudes for CMWaveX components

• frozens (iterable of bool or bool) – Indicates whether sine and cosine amplitudes of CMwavex components will be fit

Returns:

indices – Indices that have been assigned to new CMWaveX components

Return type:

list

remove_cmwavex_component(index)

Remove all CMWaveX components associated with a given index or list of indices

Parameters:

index (float, int, list, np.ndarray) – Number or list/array of numbers corresponding to CMWaveX indices to be removed from model.

get_indices()

Returns an array of intergers corresponding to CMWaveX component parameters using CMWXFREQs

Returns:

• inds (np.ndarray)

• Array of CMWaveX indices in model.

setup()

Finalize construction loaded values.

validate()

Validate loaded values.

validate_toas(toas)

Check that this model component has TOAs where needed.

add_param(param: Parameter, deriv_func: Callable | None = None, setup: bool = False)

Add a parameter to the Component.

The parameter is stored in an attribute on the Component object. Its name is also recorded in a list, self.params.

Parameters:

• param (pint.models.Parameter) – The parameter to be added.

• deriv_func (function) – Derivative function for parameter.

property aliases_map: Dict[str, str]

Return all the aliases and map to the PINT parameter name.

This property returns a dictionary from the current in timing model parameters’ aliase to the pint defined parameter names. For the aliases of a prefixed parameter, the aliase with an existing prefix index maps to the PINT defined parameter name with the same index. Behind the scenes, the indexed parameter adds the indexed aliase to its aliase list.

chromatic_time_delay(cm, alpha, freq)

Return the chromatic time delay for a set of frequencies.

delay_chrom = cm * DMconst * (freq / 1 MHz)**alpha

cm_value(toas)

Compute modeled CM value at given TOAs.

Parameters:

toas (TOAs object or TOA table(TOAs.table)) –

If given a TOAs object, it will use the whole TOA table in the

TOAs object.

Return type:

CM values at given TOAs in the unit of CM.

d_delay_d_cmparam(toas, param_name, acc_delay=None)

Derivative of delay wrt to CM parameter.

Parameters:

• toas (pint.TOAs object.) – Input toas.

• param_name (str) – Derivative parameter name

• acc_delay (astropy.quantity or numpy.ndarray) – Accumulated delay values. This parameter is to keep the unified API, but not used in this function.

property free_params_component: List[str]

Return the free parameters in the component.

This function collects the non-frozen parameters.

Return type:

A list of free parameters.

get_params_of_type(param_type: str) → List[str]

Get all the parameters in timing model for one specific Parameter subtype.

get_prefix_mapping_component(prefix: str) → Dict[int, str]

Get the index mapping for the prefix parameters.

Parameters:

prefix (str) – Name of prefix.

Returns:

A dictionary with prefix parameter real index as key and parameter name as value.

Return type:

dict

is_in_parfile(para_dict: Dict) → bool

Check if this subclass included in parfile.

Parameters:

para_dict (dictionary) – A dictionary contain all the parameters with values in string from one parfile

Returns:

Whether the subclass is included in the parfile.

Return type:

bool

match_param_aliases(alias: str) → str

Return the parameter corresponding to this alias.

Parameters:

alias (str) – Alias name.

Note

This function only searches the parameter aliases within the current component. If one wants to search the aliases in the scope of TimingModel, please use TimingModel.match_param_aliase().

param_help() → str

Print help lines for all available parameters in model.

print_par(format: Literal['tempo', 'tempo2', 'pint'] = 'pint') → str

Parameters:

format (str, optional) – Parfile output format. PINT outputs the ‘tempo’, ‘tempo2’ and ‘pint’ format. The defaul format is pint. Actual formatting done elsewhere.

Returns:

str

Return type:

formatted line for par file

register_cm_deriv_funcs(func, param)

Register the derivative function in to the deriv_func dictionaries.

Parameters:

• func (callable) – Calculates the derivative

• param (str) – Name of parameter the derivative is with respect to

register_deriv_funcs(func: Callable, param: str) → None

Register the derivative function in to the deriv_func dictionaries.

Parameters:

• func (callable) – Calculates the derivative

• param (str) – Name of parameter the derivative is with respect to

remove_param(param: str | Parameter) → None

Remove a parameter from the Component.

Parameters:

param (str or pint.models.Parameter) – The parameter to remove.