在matplotlib中绘制流数据:需要速度

时间:2016-06-26 08:04:37

标签: python-2.7 matplotlib streaming accelerometer

我从我的Android手机上传输加速计数据,并使用matplotlib成功构建了一个实时情节。我正在使用逗号运算符动态更新绘图,但我想知道是否有更优雅/ pythonic的方式来做它。要执行以下代码,您必须使用应用Sensorstream IMU+GPS。下面的代码将获取加速度计值并实时绘制它们。我根据Can you plot live data in matplotlib?绘图。就像我说的那样有效,但代码很笨拙。即使matplotlib documentation中提到的加速比例,我的运行速度约为25 FPS。这项技术,如果我只使用一个简单的情节,可以达到约90 FPS。可以证明,你可以在why is plotting with Matplotlib so slow?更快地达到~200 FPS。我找不到我的瓶颈。那么,是否有更优雅的方式来编写所有子图?第二,我可以加快密谋吗?

import socket, traceback
import matplotlib
matplotlib.use('TkAgg')
import matplotlib.pyplot as plt
from scipy.signal import butter, lfilter,iirfilter,savgol_filter
import math
import pylab
from pylab import *
import time
import numpy as np


host = ''
port = 5555

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
s.bind((host, port))

# lists for plotting
Ax = [0.0] * 50
Ay = [0.0] * 50
Az = [0.0] * 50
G  = [0.0] * 50
x = [i for i in range(len(Ax))]

#used for debugging

fig = plt.figure(figsize=(16,10))

# raw data
ax = plt.subplot("311")
ax.set_xlim(0, 50)
ax.set_ylim(-2, 2)
ax.set_title("Raw acceleration data")
ax.set_ylabel("g$/m^2$",fontsize=18)
ax.hold(True)

line  = ax.plot(Ax,label='Acc x')[0]
line2 = ax.plot(Ay,label='Acc y')[0]
line3 = ax.plot(Az,label='Acc z')[0]

# filtered data
ax2 = plt.subplot("312")
ax2.set_xlim(0, 50)
ax2.set_ylim(-2, 2)
ax2.set_title(" acceleration data")
ax2.set_ylabel("g$/m^2$",fontsize=18)
ax2.hold(True)

f_line  = ax2.plot(Ax,label='Acc x')[0]
f_line2 = ax2.plot(Ay,label='Acc y')[0]
f_line3 = ax2.plot(Az,label='Acc z')[0]

# tilt angle plot
ax3 = plt.subplot("313")
ax3.set_ylim([-180,180])
ax3.set_title("Tilt Angles")
ax3.set_ylabel("degrees",fontsize=18)
t_line = ax3.plot(G)[0]

fig.suptitle('Three-axis accelerometer streamed from Sensorstream',fontsize=18)
plt.show(False)
plt.draw()

# cache the background
background = fig.canvas.copy_from_bbox(fig.bbox)

count = 0 
print("Success binding")
while 1:
    # time it
    tstart = time.time()
    message, address = s.recvfrom(8192)
    messageString = message.decode("utf-8")
    Acc = messageString.split(',')[2:5]
    Acc = [float(Acc[i])/10.0 for i in range(3)]

    # appending and deleting is order 10e-5 sec
    Ax.append(Acc[0])
    del Ax[0]
    Ay.append(Acc[1])
    del Ay[0]
    Az.append(Acc[2])
    del Az[0]
    G.append(np.sqrt(Ax[-1]**2 + Ay[-1]**2 + Az[-1]**2))
    del G[0]

    # filter
    acc_x_savgol = savgol_filter(Ax, window_length=5, polyorder=3)
    acc_y_savgol = savgol_filter(Ay, window_length=5, polyorder=3)
    acc_z_savgol = savgol_filter(Az, window_length=5, polyorder=3)

    tilt_angles = []
    for i,val in enumerate(G): 
        angle = math.atan2(Ax[i], -1*Ay[i]) * (180 / math.pi)
        if (math.isnan(angle)):
            tilt_angles.append(0)
        else:
            tilt_angles.append(angle)

    print(Ax[0],Ay[1],Az[2])   

    line.set_xdata(x)
    line.set_ydata(Ax)
    line2.set_xdata(x)
    line2.set_ydata(Ay)
    line3.set_xdata(x)
    line3.set_ydata(Az)
    ax.set_xlim(count, count+50)

    f_line.set_xdata(x)
    f_line.set_ydata(acc_x_savgol)
    f_line2.set_xdata(x)
    f_line2.set_ydata(acc_y_savgol)
    f_line3.set_xdata(x)
    f_line3.set_ydata(acc_z_savgol)
    ax2.set_xlim(count, count+50)

    t_line.set_xdata(x)
    t_line.set_ydata(tilt_angles)
    ax3.set_xlim(count, count+50)
    # restore background
    fig.canvas.restore_region(background)

    # redraw just the points
    ax.draw_artist(line)
    ax.draw_artist(line2)
    ax.draw_artist(line3)
    ax2.draw_artist(f_line)
    ax2.draw_artist(f_line2)
    ax2.draw_artist(f_line3)
    ax3.draw_artist(t_line)

    # fill in the axes rectangle
    fig.canvas.blit(fig.bbox)

    count+=1
    x = np.arange(count,count+50,1)

    # tops out at about 25 fps :|
    print "Total time for 1 plot is: ",(time.time() - tstart)

1 个答案:

答案 0 :(得分:0)

Matplotlib documentation中所述,在向当前数字添加新图之前,您需要display()一个子图。提到plot是可选的,但建议这样做。我会附加以下代码来绘制多个子图。

plt.figure(x)