fixed hard-coded plot limits (AtsushiSakai#1018)

Author: yousefbilal

PathPlanning/RRT/rrt.py

@@ -199,7 +199,7 @@ def draw_graph(self, rnd=None):
         plt.plot(self.start.x, self.start.y, "xr")
         plt.plot(self.end.x, self.end.y, "xr")
         plt.axis("equal")
-        plt.axis([-2, 15, -2, 15])
+        plt.axis([self.min_rand, self.max_rand, self.min_rand, self.max_rand])
         plt.grid(True)
         plt.pause(0.01)