如何清除圖tkinter

Question

這段代碼很好，我想制作動態圖形，我想每60秒使我的圖形清晰可見，但是我無法使其與cla（）和clf（）一起使用，這是怎么回事？ 除了使用cla（）和clf（）之外，還有其他方法可以清除圖形嗎？

#import lib client paho mqtt
from Tkinter import *
from ttk import *
from datetime import datetime
import matplotlib
import paho.mqtt.client as mqtt
import redis, time
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.figure import Figure
from matplotlib import style 
import matplotlib.pyplot as plt
from matplotlib.pyplot import get_current_fig_manager

mqttc = mqtt.Client("serverclient",clean_session=False)#inisialisasi mqtt client
r = redis.Redis("localhost",6379)
start = time.time()
date = datetime.now().strftime('%S')
f = Figure(figsize=(5,4), dpi=100)
a = f.add_subplot(111)
b = f.add_subplot(111)
style.use('ggplot')
matplotlib.use("TkAgg")
suhu=30
cahaya=50


def mqttx():
    #fungsi callback
    def on_message(mqttc,obj,msg):
        global LED1
        global LED2
        datasuhu = r.lrange("suhu",-1,-1)
        datacahaya = r.lrange("cahaya",-1,-1)
        print "Telah Diterima message : "+msg.payload+" topik "+msg.topic
        r.rpush(msg.topic,msg.payload)

    mqttc.on_message =  on_message

    mqttc.connect("localhost",1883)

    mqttc.subscribe("suhu")
    mqttc.subscribe("cahaya")

class Example(Frame):
    def __init__(self, parent):
        Frame.__init__(self, parent)
        self.parent = parent
        self.initUI()

        self.graph()

    def initUI(self):

        self.parent.title("Subcriber")
        self.style = Style()
        self.style.theme_use("default")
        self.pack(fill=BOTH, expand=1)

        self.xList1 = []
        self.yList1 = []
        self.canvas = FigureCanvasTkAgg(f, self)

        self.canvas.show()
        self.canvas.get_tk_widget().pack(expand=True)
        thismanager = get_current_fig_manager()
        thismanager.window.wm_geometry("+500+0")


    def graph(self):
        suhu1 = r.lrange("suhu",-1,-1)
        cahaya1 = r.lrange("cahaya",-1,-1)
        date = datetime.now().strftime('%S')
        join1=str(''.join(suhu1))
        suhugraph=float(join1)

        join2=str(''.join(cahaya1))
        cahayagraph=float(join2)

        self.xList1.append(date)
        self.yList1.append(suhugraph)
        a.clear()
        a.axis([0, 100, 0, 60])
        a.plot(self.xList1, self.yList1,"r-")

        if date=="00" :
            plt.clf()
            plt.cla()
        else:

            self.canvas.draw()

        self.after(1000, self.graph)

def main():
    root = Tk()
    root.geometry("1500x1400+300+300")
    app = Example(root)

    root.mainloop()

if __name__ == '__main__':

    mqttx()
    mqttc.loop_start()
    main()

Answer 1

要清除圖形，您必須從self.xList1和self.yList1刪除數據

self.xList1 = []
self.yList1 = []

因為清除圖（ a.clear() / plt.clf() / plt.cla() ）后，您仍然在列表中有數據，然后再次繪制它們。

我無法使用Redis和mqtt運行您的代碼，所以我制作了random版本

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

import matplotlib.pyplot as plt
from matplotlib.figure import Figure

import Tkinter as tk
from datetime import datetime

import random

# --- classes --- (CamelCase names)

class Example(tk.Frame):

    def __init__(self, parent):
        tk.Frame.__init__(self, parent)
        # you don't need self.parent - tk.Frame sets self.master = parent        
        self.pack(expand=True, fill='both') # put frame inside Tk() window (and resize)

        self.x_list_1 = []
        self.y_list_1 = []

        self.initUI()

        self.draw()

    def initUI(self):
        self.fig = Figure(figsize=(5, 4), dpi=100)
        self.a = self.fig.add_subplot(111)
        self.a.axis((0, 100, 0, 60))

        self.canvas = FigureCanvasTkAgg(self.fig, self)
        self.canvas.get_tk_widget().pack(expand=True, fill='both')

    def draw(self):

        date = datetime.now().strftime('%S')
        suhugraph = random.randint(1, 60)

        if date == "00":
            self.a.clear()
            self.a.axis((0, 100, 0, 60))
            self.x_list_1 = []
            self.y_list_1 = []

        self.x_list_1.append(date)
        self.y_list_1.append(suhugraph)

        self.a.plot(self.x_list_1, self.y_list_1, "r-")
        self.canvas.draw()

        self.after(1000, self.draw)

# --- functions --- (lower_case names)

def main():
    root = tk.Tk()
    app = Example(root)
    root.mainloop()

# --- main ---

if __name__ == '__main__':
    main()

順便說一句： matplotlib：清除繪圖，何時使用cla（），clf（）或close（）？

---

至於調整大小后的響應-問題可能是代碼中的兩個循環： root.mainloop()和mqttc.loop_start() 。 我無法使用mqttc運行代碼，因此無法對其進行測試。

---

順便說一句：不使用plot()和clear()更新圖

首先創建空行

self.line, = self.a.plot([], [], "r-")

然后您替換所有數據

self.line.set_xdata( self.x_list_1 )
self.line.set_ydata( self.y_list_1 )

因此您不需要clear()並再次設置軸。

import matplotlib
matplotlib.use("TkAgg")
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

import matplotlib.pyplot as plt
from matplotlib.figure import Figure

import Tkinter as tk
from datetime import datetime

import random

# --- classes --- (CamelCase names)

class Example(tk.Frame):

    def __init__(self, parent):
        tk.Frame.__init__(self, parent)
        # you don't need self.parent - tk.Frame sets self.master = parent        
        self.pack(expand=True, fill='both') # put frame inside Tk() window (and resize)

        self.x_list_1 = []
        self.y_list_1 = []

        self.initUI()

        self.draw()

    def initUI(self):
        self.fig = Figure(figsize=(5, 4), dpi=100)
        self.a = self.fig.add_subplot(111)
        self.a.axis((0, 100, 0, 60))

        self.canvas = FigureCanvasTkAgg(self.fig, self)
        self.canvas.get_tk_widget().pack(expand=True, fill='both')

        # create empty line 
        self.line, = self.a.plot([], [], "r-")

    def draw(self):

        date = datetime.now().strftime('%S')
        suhugraph = random.randint(1, 60)

        if date == "00":
            self.x_list_1 = []
            self.y_list_1 = []

        self.x_list_1.append(date)
        self.y_list_1.append(suhugraph)

        # update data in line without `plot()` (and without `clear()`)
        self.line.set_xdata( self.x_list_1 )
        self.line.set_ydata( self.y_list_1 )

        self.canvas.draw()

        self.after(1000, self.draw)

# --- functions --- (lower_case names)

def main():
    root = tk.Tk()
    app = Example(root)
    root.mainloop()

# --- main ---

if __name__ == '__main__':
    main()