Source code for einsteinpy.geodesic.null
from einsteinpy.geodesic import Geodesic
[docs]class Nulllike(Geodesic):
"""
Class for defining Null-like Geodesics
"""
def __init__(
self,
position,
momentum,
a=0.0,
end_lambda=50.0,
step_size=0.0005,
return_cartesian=True,
julia=True,
):
"""
Constructor
Parameters
----------
position : array_like
Length-3 Array, containing the initial 3-Position
momentum : array_like
Length-3 Array, containing the initial 3-Momentum
a : float, optional
Dimensionless Spin Parameter of the Black Hole
``0 <= a <= 1``
Defaults to ``0.`` (Schwarzschild Black Hole)
end_lambda : float, optional
Affine Parameter value, where integration will end
Equivalent to Proper Time for Timelike Geodesics
Defaults to ``50.``
step_size : float, optional
Size of each geodesic integration step
A fixed-step, symplectic VerletLeapfrog integrator is used
Defaults to ``0.0005``
return_cartesian : bool, optional
Whether to return calculated positions in Cartesian Coordinates
This only affects the coordinates. The momenta dimensionless quantities,
and are returned in Spherical Polar Coordinates.
Defaults to ``True``
julia : bool, optional
Whether to use the julia backend
Defaults to ``True``
"""
super().__init__(
position=position,
momentum=momentum,
a=a,
end_lambda=end_lambda,
step_size=step_size,
time_like=False,
return_cartesian=return_cartesian,
julia=julia,
)