Inspired by a Pinterest post on what joining 2 planets' positions over several years looks like, I wrote this code to verify it.
lines.ipynb contains all the tunabke parameters.
pl1_rad = radius of planet with smaller orbit
pl2_rad = radius of the other planet
fraction = ratio of revolutionary periods of 1 and 2 in earth years
outer_turn_angle = number of revolutions of outer planet to consider in the plot
one_round_steps = steps to consider in one revolution. 100 gives a good plot.
figname = output figure name
linewidth = linewidth (points) for each line in the plot
This code considers circular orbits for both planets. It can be modified for elliptical orbits by using (a cosθ, b sinθ) instead of (r cosθ, r sinθ) while plotting the coordinates.
This code also considers that both planets start from angle 0. This may not always be the case, but its effects dilute with more number of turns (i.e. a higher outer_turn_angle).
Some of the plots:
(32*2*pi in place of outer_turn_angle)
