fixed error

plots/animation.py

 import numpy as np
 from matplotlib import pyplot as plt
-from matplotlib.animation import FuncAnimation
+import matplotlib.animation as animation
 
 data = np.loadtxt("../out/positions.dat")
 print(data.shape)
@@ -19,11 +19,13 @@ def animate(i):
     xi = x[i*N:(i+1)*N]
     yi = y[i*N:(i+1)*N]
     plt.cla()
-    plt.scatter(xi, yi, s=1)
+    plt.scatter(xi, yi, s=0.1)
+    plt.xlabel("x")
+    plt.ylabel("y")
+    plt.axis("equal")
     plt.xlim(-1, 1)
     plt.ylim(-1, 1)
-    plt.axis("equal")
 
-animation = FuncAnimation(fig, animate, frames=nSteps)
-mp4writer = animation.FFMpegWriter(fps=30)
-animation.save("animation.mp4", writer=mp4writer)
\ No newline at end of file
+anim = animation.FuncAnimation(fig, animate, frames=nSteps)
+mp4writer = animation.FFMpegWriter(fps=24)
+anim.save("animation.mp4", writer=mp4writer, dpi=100)
\ No newline at end of file