lalsimulation.nrfits.eval_fits Namespace Reference

Data Structures
class	FitAttributes
	Saves attributes of a particular fit. More...

Functions
def	truncate_output_to_physical_limits (val_dict, behavior)
	Function to truncate fit values when they go beyond the following physical limits: More...
def	check_extra_params_and_set_defaults (extra_params_dict)
	Does some sanity checks on extra_params_dict. More...
def	eval_nrfit (m1, m2, chiA_vec, chiB_vec, model_name, fit_types_list, f_ref=-1, extra_params_dict=None)
	Evaluates Numerical Relativity fits for a given model. More...

Variables
dictionary	fits_collection = {}
	fit_class
	desc
	refs
	model_keywords

Function Documentation

truncate_output_to_physical_limits()

def lalsimulation.nrfits.eval_fits.truncate_output_to_physical_limits	(		val_dict,
			behavior
	)

Function to truncate fit values when they go beyond the following physical limits:

• FinalMass: 1, FinalMass is expected as a fraction of total mass here.
• FinalSpin: magnitude = 1, the Kerr limit for dimensionless spins.
• RecoilKick: magnitude = 1, as this is in units of c.

Inputs:

• val_dict: A dictionary of fits with one or more of the above keys. See eval_nrfit.
• behavior (str) can be one of the following:
  • "TRUNCATE": Rescale output magnitude to maximum limit, with an info message.
  • "TRUNCATESILENT": Rescale output magnitude to maximum limit, without info message
  • "KEEP": Keep output magnitude, even if unphysical, but still give the info message
  • "IGNORE": Keep output magnitude, even if unphysical, without info message
  • "ERROR": Abort with an error if output magnitude is unphysical.

Definition at line 93 of file eval_fits.py.

check_extra_params_and_set_defaults()

def lalsimulation.nrfits.eval_fits.check_extra_params_and_set_defaults

(

extra_params_dict

)

Does some sanity checks on extra_params_dict.

If any of the default_keywords are not specified, sets them to the default values.

Definition at line 142 of file eval_fits.py.

eval_nrfit()

def lalsimulation.nrfits.eval_fits.eval_nrfit	(		m1,
			m2,
			chiA_vec,
			chiB_vec,
			model_name,
			fit_types_list,
			f_ref = -1,
			extra_params_dict = None
	)

Evaluates Numerical Relativity fits for a given model.

• m1: mass of object 1 in kg.
  This needs to be in kg for models that allow f_ref != -1. When f_ref = -1, if other units are used for m1/m2, the remnant mass will be returned in the same units.
  
• m2: mass of the object 2 in kg.
  
• chiA_vec: dimensionless spin (3-vector) of object 1 at the reference epoch.
  
• chiB_vec: dimensionless spin (3-vector) of object 2 at the reference epoch.
  This follows the same convention as the waveform interface (see https://dcc.ligo.org/T1800226/public), where the spin components are defined as:
  • \(\chi_z = \chi \cdot \hat{L}\), where \(L\) is the orbital angular momentum vector at the reference epoch.
  • \(\chi_x = \chi \cdot \hat{n}\), where \(n =\) body2 -> body1 is the separation vector pointing from body2 to body1 at the reference epoch.
  • \(\chi_y = \chi \cdot (\hat{L} \times \hat{n})\).
    These spin components are frame-independent as they are defined using vector inner products. One can also think of the above spins as being defined in the following reference frame: The positive z-axis is along the orbital angular momentum at the reference epoch. The separation vector from the object 2 to object 1 at the reference epoch is along the positive x-axis. The y-axis completes the right-handed triad. The returned vectors such as final spin and kick velocity are also defined in the same frame.
• model_name: model used for fit.
  See lalsimulation.nrfits.eval_fits.fits_collection.keys() for all available fits. Details about a particular model, including its validity, can be found by doing the following:
  >> from lalsimulation.nrfits.eval_fits import fits_collection
  >> help(fits_collection[model_name].fit_class)
• fit_types_list: List of fits to evaluate.
  Allowed values for elements are "FinalMass", "FinalSpin", "RecoilKick", and "PeakLuminosity".
  Example: fit_types_list = ["FinalMass", "FinalSpin"]
• f_ref: reference frequency (in Hz) used to set the reference epoch.
  The reference epoch is set such that the orbital frequency is equal to f_ref/2. If f_ref = -1, the reference epoch is taken to be the time/frequency at which the fits were constructed. This can be different for different models, see the documentation for the specific model. Default: f_ref = -1.
• extra_params_dict: Any additional parameters required for a specific model. Default: None.
  Allowed keys for extra_params_dict are:
  • Lambda1: Tidal deformability of object 1. Default: None.
  • Lambda2: Tidal deformability of object 2. Default: None.
  • eccentricity: Eccentricity at the reference epoch. Default: None.
  • mean_anomaly: Mean anomaly at the reference epoch. Default: None.
  • unlimited_extrapolation: Some models will raise an error if evaluated well outside their calibration range. If unlimited_extrapolation = True, then these errors are not raised and the model will still produce an output. USE AT YOUR OWN RISK!! Default: False.
  • physical_limit_violation_behavior: What to do if the fit values violate physical limits FinalMass > total mass, |FinalSpin| > 1, or |RecoilKick| > 1.
    Allowed options are (Default: "ERROR"):
    • "ERROR": Abort with an error message.
    • "TRUNCATE": Rescale output magnitude to maximum limit, with a warning.
    • "TRUNCATESILENT": Rescale output magnitude to maximum limit, without warning.
    • "KEEP": Keep output magnitude, but with a warning.
    • "IGNORE": Keep output magnitude, without warning.
• Returns: return_dict.
  Dictionary of values corresponding to the keys in fit_types_list.
  Example: mf = return_dict["FinalMass"]

Definition at line 262 of file eval_fits.py.

Variable Documentation

fits_collection

dictionary lalsimulation.nrfits.eval_fits.fits_collection = {}

Definition at line 48 of file eval_fits.py.

fit_class

lalsimulation.nrfits.eval_fits.fit_class

Definition at line 51 of file eval_fits.py.

desc

lalsimulation.nrfits.eval_fits.desc

Definition at line 52 of file eval_fits.py.

refs

lalsimulation.nrfits.eval_fits.refs

Definition at line 55 of file eval_fits.py.

model_keywords

lalsimulation.nrfits.eval_fits.model_keywords

Definition at line 56 of file eval_fits.py.