View difference between Paste ID: y46tfBXL and m9knmtU7

-from matplotlib import pyplot as plt
+#!/usr/bin/env python
-from matplotlib import animation
+
-
+from matplotlib import pyplot as plt
-
+from matplotlib import animation
-class Particle:
+
-
+
-    def __init__(self, x, y, ang_speed):
+class Particle:
-        self.x = x
+
-        self.y = y
+    def __init__(self, x, y, ang_speed):
-        self.ang_speed = ang_speed
+        self.x = x
-
+        self.y = y
-
+        self.ang_speed = ang_speed
-class ParticleSimulator:
+
-
+
-    def __init__(self, particles):
+class ParticleSimulator:
-        self.particles = particles
+
-
+    def __init__(self, particles):
-    def evolve(self, dt):
+        self.particles = particles
-        timestep = 0.00001
+
-        nsteps = int(dt / timestep)
+    def evolve(self, dt):
-
+        timestep = 0.00001
-        for i in range(nsteps):
+        nsteps = int(dt / timestep)
-            for p in self.particles:
+
-
+        for i in range(nsteps):
-                # 1. calculate the direction
+            for p in self.particles:
-                norm = (p.x ** 2 + p.y ** 2) ** 0.5
+
-                v_x = (-p.y) / norm
+                # 1. calculate the direction
-                v_y = p.x / norm
+                norm = (p.x ** 2 + p.y ** 2) ** 0.5
-
+                v_x = (-p.y) / norm
-                # 2. calculate the displacement
+                v_y = p.x / norm
-                d_x = timestep * p.ang_speed * v_x
+
-                d_y = timestep * p.ang_speed * v_y
+                # 2. calculate the displacement
-
+                d_x = timestep * p.ang_speed * v_x
-                p.x += d_x
+                d_y = timestep * p.ang_speed * v_y
-                p.y += d_y
+
-
+                p.x += d_x
-                # 3. repeat for all the time steps
+                p.y += d_y
-
+
-
+                # 3. repeat for all the time steps
-def visualize(simulator):
+
-    X = [p.x for p in simulator.particles]
+
-    Y = [p.y for p in simulator.particles]
+def visualize(simulator):
-
+    X = [p.x for p in simulator.particles]
-    fig = plt.figure()
+    Y = [p.y for p in simulator.particles]
-    ax = plt.subplot(111, aspect='equal')
+
-    line, = ax.plot(X, Y, 'ro')
+    fig = plt.figure()
-
+    ax = plt.subplot(111, aspect='equal')
-    # Axis limits
+    line, = ax.plot(X, Y, 'ro')
-    plt.xlim(-1, 1)
+
-    plt.ylim(-1, 1)
+    # Axis limits
-
+    plt.xlim(-1, 1)
-    # It will be run when the animation starts
+    plt.ylim(-1, 1)
-    def init():
+
-        line.set_data([], [])
+    # It will be run when the animation starts
-        return line,
+    def init():
-
+        line.set_data([], [])
-    def animate(i):
+        return line,
-        # We let the particle evolve for 0.1 time units
+
-        simulator.evolve(0.01)
+    def animate(i):
-        X = [p.x for p in simulator.particles]
+        # We let the particle evolve for 0.1 time units
-        Y = [p.y for p in simulator.particles]
+        simulator.evolve(0.01)
-
+        X = [p.x for p in simulator.particles]
-        line.set_data(X, Y)
+        Y = [p.y for p in simulator.particles]
-        return line,
+
-
+        line.set_data(X, Y)
-    # Call the animate function each 10 ms
+        return line,
-    anim = animation.FuncAnimation(fig, animate,
+
-                                   init_func=init,
+    # Call the animate function each 10 ms
-                                   blit=True,
+    anim = animation.FuncAnimation(fig, animate,
-                                   # Efficient animation
+                                   init_func=init,
-                                   interval=10)
+                                   blit=True,
-    plt.show()
+                                   # Efficient animation
-
+                                   interval=10)
-    def test_visualize():
+    plt.show()
-        particles = [Particle(0.3,  0.5,  +1),
+
-                     Particle(0.0,  -0.5, -1),
+    def test_visualize():
-                     Particle(-0.1, -0.4, +3)]
+        particles = [Particle(0.3,  0.5,  +1),
-
+                     Particle(0.0,  -0.5, -1),
-        simulator = ParticleSimulator(particles)
+                     Particle(-0.1, -0.4, +3)]
-        visualize(simulator)
+
-
+        simulator = ParticleSimulator(particles)
-    if __name__ == '__main__':
+        visualize(simulator)
 
     if __name__ == '__main__':
         test_visualize()