Made some changes

src/scripts/plot_2_particles.py

@@ -34,13 +34,18 @@ def main():
         "seagreen",
         "darkred"
     ]
+    start_pos = set()
     for label, color, file in zip(labels, colors, files):
         with open(file) as f:
             lines = f.readlines()
             t = np.linspace(0, 50, len(lines))
             r = np.array([list(map(float, line.strip().split(","))) for line in lines])
             plt.plot(r[:,0], r[:,1], label=label, color=color)
+            start_pos.add((r[0,0],r[0,1]))
     
+    for pos in start_pos:
+        plt.plot(*pos, "o", color="black")
+
     plt.xlabel(r"x $(\mu m)$")
     plt.ylabel(r"y $(\mu m)$")
     plt.legend(loc="upper right")