Line animation, featuring pirates. Answer to https://stackoverflow.com/questions/51482082/animate-a-point-moving-along-path-between-two-points

animate_along_great_circle.py

import cartopy.crs as ccrs
import matplotlib.animation as animation
import matplotlib.pyplot as plt

ax = plt.axes(projection=ccrs.Robinson())
ax.stock_img()

ny_lon, ny_lat = -75, 43
delhi_lon, delhi_lat = 77.23, 28.61

[line] = plt.plot([ny_lon, delhi_lon], [ny_lat, delhi_lat],
         color='blue', linewidth=2, marker='o',
         transform=ccrs.Geodetic(),
         )

t_path = line._get_transformed_path()
path_in_data_coords, _ = t_path.get_transformed_path_and_affine()


# Draw the point that we want to animate.
[point] = plt.plot(ny_lon, ny_lat, marker='o', transform=ax.projection)

def animate_point(i):
    verts = path_in_data_coords.vertices
    i = i % verts.shape[0]
    # Set the coordinates of the line to the coordinate of the path.
    point.set_data(verts[i, 0], verts[i, 1])

ani = animation.FuncAnimation(
    ax.figure, animate_point,
    frames= path_in_data_coords.vertices.shape[0],
    interval=125, repeat=True)

ani.save('point_ani.gif', writer='imagemagick')
plt.show()

arrrr.gif

pirates.png

point_ani.gif

project_line_ani.py

project_line_ani_img.py

projected_line_ani.gif