Module cosmicBallet.utils.binaryBH
This module contains functions to generate binary black hole waveforms and trajectories. This script is a modified version of the binaryBHexp module that aims to visualize the trajectories of binary black hole mergers using matplotlib animations with trajectories interpolated from data generated by the NRSur7dq2 module. The original copyright and scripting is credited to:
copyright: Copyright (C) 2018 Vijay Varma email: vvarma@caltech.edu author: Vijay Varma license: MIT GitHub Link: https://github.com/vijayvarma392/binaryBHexp/tree/master git clone link: https://github.com/vijayvarma392/binaryBHexp.git
Functions
def get_binary_data(q: float, chiA:-
Function that generates binary black hole waveforms and trajectories.
Args
q:float- mass ratio
chiA:np.array- dimensionless spin of object A
chiB:np.array- dimensionless spin of object B
omega_ref:np.array- reference frequency
omega_start:np.array, optional- start frequency. Defaults to None.
uniform_time_step_size:int, optional- uniform time step size. Defaults to None.
Returns
tuple- Trajectories and waveforms of the binary system
def get_omegaOrb_from_sparse_data(t_sparse:-
Function that computes orbital frequency from sparse data using splines.
Args
t_sparse:np.array- Sparse time array
phiOrb_sparse:np.array- Sparse orbital phase array
Returns
omegaOrb_spl (np.array): Orbital frequency array
def get_separation_from_omega(omega:-
Function that calculates the separation of the binary system from the orbital frequency and other parameters.
The separation from omega is not scientifically verified and is only used for visualization purposes (original author's note).Args
omega:np.array- Orbital frequency array
mA:float- Mass of component A
mB:float- Mass of component B
chiA:np.array- Spin of component A
chiB:np.array- Spin of component B
LHat:np.array- Angular Momentum unit vector
pnorder:float- Post-Newtonian order (defaults to 3.5 PN)
Returns
r (np.array): Separation array
def get_trajectory(separation:-
Function that determines the trajectory of a component in a binary given the separation, the coprecessing frame quaternion and orbital phase in the coprecessing frame.
Args
separation:np.array- Separation of the binary
quat_nrsur:np.array- Quaternion of the binary system
orbphase_nrsur:np.array- Orbital phase of the binary system
bh_label:str- Label of the black hole component
def get_uniform_in_orbits_times(t:-
Function that calculates the time array for the binary system simulation.
Args
t:np.array- Time array of the simulation
phi_orb:np.array- Orbital phase array of the simulation
PTS_PER_ORBIT:int- Number of points per orbit
Returns
t_sparse (np.array): Time array for the binary system simulation
def spline_interp(newX:-
Function that interpolates data using splines.
Args
newX:np.array- New x values
oldX:np.array- Old x values
oldY:np.array- Old y values
allowExtrapolation:bool- Flag to allow extrapolation
Returns
newY (np.array): New y values