Live Plot in Python GUI

I am trying to write a Python GUI and I need to do a live plot. I currently have a program that receives data from a machine I am using and I want to be able to plot the values the machine outputs as I receive them. I have been researching and from what I have found so far, it doesn't seem to me like tkinter or any library can do this in a GUI. Does anyone know whether and how tkinter can do this or if there is another library that is capable of doing such a live plot?

Also, how would I go about writing the data that I gather to a file as I receive the data?

Thanks in advance for your help.

It looks like you get the data by polling, which means you don't need threads or multiple processes. Simply poll the device at your preferred interface and plot a single point.

Here's an example with some simulated data to illustrate the general idea. It updates the screen every 100ms.

import Tkinter as tk
import random

class ServoDrive(object):
    # simulate values
    def getVelocity(self): return random.randint(0,50)
    def getTorque(self): return random.randint(50,100)

class Example(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        self.servo = ServoDrive()
        self.canvas = tk.Canvas(self, background="black")
        self.canvas.pack(side="top", fill="both", expand=True)

        # create lines for velocity and torque
        self.velocity_line = self.canvas.create_line(0,0,0,0, fill="red")
        self.torque_line = self.canvas.create_line(0,0,0,0, fill="blue")

        # start the update process
        self.update_plot()

    def update_plot(self):
        v = self.servo.getVelocity()
        t = self.servo.getTorque()
        self.add_point(self.velocity_line, v)
        self.add_point(self.torque_line, t)
        self.canvas.xview_moveto(1.0)
        self.after(100, self.update_plot)

    def add_point(self, line, y):
        coords = self.canvas.coords(line)
        x = coords[-2] + 1
        coords.append(x)
        coords.append(y)
        coords = coords[-200:] # keep # of points to a manageable size
        self.canvas.coords(line, *coords)
        self.canvas.configure(scrollregion=self.canvas.bbox("all"))

if __name__ == "__main__":
    root = tk.Tk()
    Example(root).pack(side="top", fill="both", expand=True)
    root.mainloop()

chase

As far as I understand it, it can be done with tkinter/Qt/wxpython etc. You just have to make use of mutlithreading and multiprocessing. There may be a simpler way to do it with another module, but I am unaware of it.

I have been looking into something similar to this problem for a long time as well, and it appears that it is a constant issue among this community.

Here are some threads which talk about the issue:

How do I refresh a matplotlib plot in a Tkinter window?

How do I update a matplotlib figure while fitting a function?

来源：https://stackoverflow.com/questions/15736393/live-plot-in-python-gui

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