Question

我正在尝试在python中构造一个实时图形以在具有固定绘图窗口的图形中绘制随机数绘图窗口的宽度为20个样本。对于第21个样本，第一个样本将从右侧消失。这是我的代码。无法弄清楚为什么不绘图。

import random 
import time
import matplotlib.pyplot as plt
import matplotlib.animation as animation
fig = plt.figure()
#creating a subplot 
ax1 = fig.add_subplot(1,1,1)
xs = []
ys = []
iter = 0
def animate(i,xs,ys,iter):
    while True:
        iter = iter+1
        xs.append(iter)
        ys.append(round(random.uniform(-120,20),2))
#I want only 20 data points on the plot i.e the plot window will be only showing 20 samples at a time 
        x = xs[-20:]
        y = ys[-20:]
        ax1.clear()
        ax1.plot(x, y)
        ax1.set_ylim([-120,20])
        plt.xlabel('Value')
        plt.ylabel('Time')
        plt.title('Live Graph')
        time.sleep(1)   

ani = animation.FuncAnimation(fig, animate, fargs = (xs,ys,iter), interval=1000) 
plt.show()

Answer 1

签出documentation for FuncAnimation。

第二个参数是针对每个连续帧重复调用的函数，每次调用都会更新图形。您的函数animate是一个无限循环，因此执行线程永远不会返回到FuncAnimation。尝试这样的方法作为起点：

import random 
import time
import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig = plt.figure()
ax1 = fig.add_subplot(1,1,1)
xs = []
ys = []
line, = ax1.plot(xs, ys)
plt.xlabel('Value')
plt.ylabel('Time')
plt.title('Live Graph')

def animate(frame, xs, ys):
    xs.append(frame)
    ys.append(round(random.uniform(-120,20),2))
    x = xs[-20:]
    y = ys[-20:]
    line.set_xdata(x)
    line.set_ydata(y)
    ax1.set_xlim(min(x)-1, max(x)+1)
    ax1.set_ylim(min(y)-1, max(y)+1)
    ax1.set_xticks(list(range(min(x), max(x)+1)))
    return line

ani = animation.FuncAnimation(fig, animate, fargs = (xs,ys), interval=100) 
plt.show()

带有固定窗口的python动态图

1 个答案: