在x轴上绘制数据时间并使用python实时调整

Question

I want to plot real time serial data against time on x axis. I want x axis to change dynamically ie when I get new data the window length should remain same but the x axis should shift.

So far I have been able to plot the serial data sample sample points and I am not able to change the x axis but the y axis values keep on changing.

I took the help of the given code which I got from this forum itself

import matplotlib.pyplot as plt
import time
import random
from collections import deque
import numpy as np


def random_gen():
    while True:
        val = random.randint(1,10)
        yield val
        time.sleep(0.1)


a1 = deque([0]*100)
ax = plt.axes(xlim=(0, 20), ylim=(0, 10))
d = random_gen()

line, = plt.plot(a1)
plt.ion()
plt.ylim([0,10])
plt.show()

for i in range(0,20):
    a1.appendleft(next(d))
    datatoplot = a1.pop()
    line.set_ydata(a1)
    plt.draw()
    plt.pause(0.0001) 

I have changed the random_gen() part for my case and I am plotting serial data but I am giving this code because otherwise I would have give to serial data in a file which will only make things complicated.

I found this code which can be used to find the time values

import datetime

dlist = deque([datetime.datetime.now()] * 100)

while 1:
    # collect the data .........

    dlist.appendleft((datetime.datetime.now()))

I have no idea how to change x axis dynamically.

I am new to python and there might be some things that I may be doing wrong so please ignore those

Please give some suggestions.

Thanks

Answer 1

Perhaps I misunderstand your question, but couldn't you use plt.xlim() and update it every time you add new data? Using your example the loop would change to:

for i in range(0,20):
    a1.appendleft(next(d))
    datatoplot = a1.pop()
    line.set_ydata(a1)
    plt.xlim(0, 20 + i)
    plt.draw()
    plt.pause(0.0001)