Animations in EinsteinPy

Importing required modules

[1]:
import numpy as np

from einsteinpy.geodesic import Timelike
from einsteinpy.plotting import StaticGeodesicPlotter

Defining various parameters

  • Initial position & momentum of the test partcle

  • Spin of the Kerr Black Hole in metric_params

  • Other solver parameters

Note that, we are working in M-Units (\(G = c = M = 1\)).

[2]:
# Constant Radius Orbit
position = [4, np.pi / 3, 0.]
momentum = [0., 0.767851, 2.]
a = 0.99
steps = 400.
delta = 0.5

Calculating geodesic

[3]:
geod = Timelike(
    metric="Kerr",
    metric_params=(a,),
    position=position,
    momentum=momentum,
    steps=steps,
    delta=delta,
    return_cartesian=True
)

Animating

[4]:
%matplotlib widget
# Use %matplotlib ipympl instead if you are working in Visual Studio Code.
# You may need to `pip install ipympl` first.
sgpl = StaticGeodesicPlotter()
sgpl.animate(geod, interval=1)
sgpl.show()

Saving animation as .gif

[5]:
# You may need to install imagemagick separately to save the animation as a gif
# sgpl.ani.save('animation.gif', writer='imagemagick', fps=30)