【案例】matplotlib 实时动态绘制多条曲线

• • 效果图
  • 源代码

纵坐标中的数据比较密集，不过不碍事，这个 GIF 主要想要说明程序运行效果。

程序应该很好理解，请忽略我设置的全局参数，这些不重要，程序逻辑很清楚。

import random
from math import pi, sin
import threading
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.animation as animation
from scipy import signal

#用于显示正常中文标签
plt.rcParams['font.sans-serif']=['SimHei']
#用于正常显示负号
plt.rcParams['axes.unicode_minus'] = False

RANGE = 1000
START_Y = 0
END_Y = 1000
FREQUENCY = 10
KEY = 0
LastDistance = -1
Jitter_Threshold = 20
onlyonce = 0

fig = plt.figure()
ax = plt.axes(xlim=(0, RANGE), ylim=(0, RANGE))
# ax.legend(loc='best')
ax.grid(axis='both')
x_ticks = np.arange(0, RANGE, 5*FREQUENCY)
y_ticks = np.arange(0, RANGE, 2*FREQUENCY)
plt.xticks(x_ticks)
plt.yticks(y_ticks)
x_line = [i for i in range(0, RANGE)]
y_line = [0.0 for i in range(0, RANGE)]
x_sin_line = [i for i in range(0, RANGE)]
y_sin_line = [0.0 for i in range(0, RANGE)]
x_square_line = [i for i in range(0, RANGE)]
y_square_line = [0.0 for i in range(0, RANGE)]
plt.ylim(bottom=START_Y, top=END_Y)

line, = plt.plot(x_line, y_line, linestyle='-', label='Real-time curve', linewidth=1, color='blue')
line_sin, = plt.plot(x_sin_line, y_sin_line, linestyle='-', label='', linewidth=1, color='red')
line_square, = plt.plot(x_square_line, y_square_line, linestyle='-', label='', linewidth=1, color='green')
text_ani = plt.text(900, 750, '', ha='center', va= 'bottom', fontsize=20)

sinx_g = None # data_from_sinx(A=1, w=1, f=0, h=0, step=1000) generator
square_wave_g = None

def draw():
    def update(c):
        x_line = [i for i in range(0, RANGE)]
        # 绘制随机数曲线
        distance = data_from_random()
        y_line.pop(-1)
        y_line.insert(0, distance)
        line.set_data(x_line, y_line)

        # 绘制sin曲线，需要注意return
        x_sin_line = [i for i in range(0, RANGE)]
        y_sin_line.pop(-1)
        y_sin_line.insert(0, sinx_g.__next__()[1])
        line_sin.set_data(x_sin_line, y_sin_line)

        # 绘制方波曲线，需要注意return
        x_square_line = [i for i in range(0, RANGE)]
        y_square_line.pop(-1)
        y_square_line.insert(0, square_wave_g.__next__()[1])
        line_square.set_data(x_square_line, y_square_line)

        # 显示当前数值
        text_ani.set_text("d= %.3f" % distance)

        return line, line_sin, line_square, text_ani # 将需要动态变化的内容return即可
    anim = animation.FuncAnimation(fig=fig, func=update, interval=FREQUENCY, blit=True)
   
    anim.save("text.gif", writer='pillow')
    plt.show()

def data_from_square_wave(A=100, hz=20, h=0, step=1000):
    """
    A: 振幅
    hz：频率
    h：位移高度
    """
    t = 0
    y = 0
    while True:
        y = signal.square(2 * np.pi * hz * t)
        yield t, A*y + h
        t += 1/step

def data_from_sinx(A=1, w=1, f=0, h=0, n=0, step=1000):
    """
    @param A: 振幅
    @param w: 频率 弧度制
    @param f: 相位 弧度制
    y = Asin(wx+f)
    """
    x = -2*pi
    while True:
        x += 1/step
        y = pow(A*sin(w*x + f) + h, n)
        yield x, y


def data_from_random():
    """
    返回[0, 500]间的随机整数
    """
    return random.randint(0, 500)

if __name__ == "__main__":
    sinx_g = data_from_sinx(A=50, w=4*pi, f=0, h=(START_Y+END_Y)/2+START_Y, n=1, step=1000)
    square_wave_g = data_from_square_wave(A=100, hz=20, h=(START_Y+END_Y)/2+START_Y, step=1000)
    threading.Thread(target=draw()).start()