Question

我在python中使用matplotlib时遇到了一小段代码，想要一些帮助。我试图在python中使用matplotlib包在python中制作两个盒子车的动画，但是我无法获得animate函数来同时更新两个汽车的x坐标。

下面给出了一个最小的工作示例：

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as patches
import matplotlib.animation as animation

# Complete length of trajectory 
maxL = 2000

# Initial positions and velocities of lead and host cars
xl = 30
vl = 5

xh = 0
vh = 5

# Step size 
dt = 0.1 

lead = np.matrix([[xl,vl]])
host = np.matrix([[xh,vh]])

while xl < maxL:
    xl = xl + vl*dt
    lead = np.concatenate((lead,[[xl,vl]]), axis = 0)
    xh = xh + vh*dt
    host = np.concatenate((host,[[xh,vh]]), axis = 0)

road_width = 3;
fig1 = plt.figure(1)
ax = fig1.add_subplot(111)
rect_l = patches.Rectangle(
         (lead[0,0], road_width/2),   # (x,y)
         10,          # width
         1,          # height
         facecolor = "red", # remove background
         )
rect_h = patches.Rectangle(
          (host[0,0], road_width/2),   # (x,y)
          10,          # width
          1,          # height
          facecolor = "blue", # remove background
          )

ax.add_patch(rect_l)
ax.add_patch(rect_h)

def init():
    plt.plot([0,maxL],[road_width,road_width],'k-')
    plt.plot([0,maxL],[-road_width,-road_width],'k-')
    plt.plot([0,maxL],[0,0],'k--')
    return []

#### This works #####
def animate(x1):
    rect_l.set_x(x1)
    return rect_l,


plt.axis([0, maxL, -10, 10])
plt.xlabel('time (s)')
plt.ylabel('road')
plt.title('Car simulation')
ani = animation.FuncAnimation(fig1, animate, lead[:,0], init_func = init, interval=0.1, blit=False)

plt.show()

但我想要下面的东西。 Python在运行此代码时崩溃。

def animate(x1,x2):
    rect_l.set_x(x1)
    rect_h.set_x(x2)
    return rect_l,rect_h,


plt.axis([0, maxL, -10, 10])
plt.xlabel('time (s)')
plt.ylabel('road')
plt.title('Car simulation')
ani = animation.FuncAnimation(fig1, animate, (lead[:,0],host[:,0]), init_func = init, interval=0.1, blit=False)

plt.show()

Answer 1

您可以为frames参数提供帧数，而不是用于绘图的值。

ani = animation.FuncAnimation(fig1, animate, frames=len(lead) )

这相当于使用0和len(lead)之间的范围，并使用当前帧的整数调用动画。您可以使用此数字从动画函数中的lead和host数组中选择适当的值。

def animate(i):
    x1 = lead[i,0]
    x2 = host[i,0]
    rect_l.set_x(x1)
    rect_h.set_x(x2)

在matplotlib中为funcAnimation添加参数

1 个答案: