在 PyQt5 中清除并重新填充 Matplotlib？

Question

我想在按下刷新按钮后用新数据更新图表。为此，我想删除或清除现有图表，然后重新创建它。我在我的PyQt5 GUI 窗口中使用matplotlib。更具体地说，我的 matplotlib 图的父级是 PyQt5 GroupBox。

这是我用来构建情节的代码：

def initEventGraph(self, parent, numDays=7): 
    self.canvas = FigureCanvas(plt.Figure(figsize=(6.31,4.75), dpi=80))
    self.canvas.setParent(parent)
    self.canvas.move(10,20)

    self.ax = self.canvas.figure.subplots()

    FigureCanvas.setSizePolicy(self,
            QSizePolicy.Expanding,
            QSizePolicy.Expanding)
    FigureCanvas.updateGeometry(self)

    self.plot(num_days=numDays)

这是我用来将数据应用于绘图的代码：

def plot(self,num_days):
    current_time = datetime.datetime.now()
    events = self.findXDayOldEvents(days=num_days, current_time=current_time) 
    sorted_events = self.sortEventList(events)

    for event_name, entries in sorted_events.items(): 
        x_axis = entries["Time"]
        y_axis = entries["Channel"]
        color = entries["Color"]
        self.ax.scatter(x_axis, y_axis,color=color, label=event_name)
        self.ax.tick_params(labelrotation=15)
    self.ax.legend()
    self.ax.set_ylabel("Channel")
    self.ax.grid()

我尝试了几种不同的方法，涉及clear()、clf() 和cla()。除了其他各种方法之外，我一直无法清除或删除现有的情节。

我想要清除我现有的情节，然后再次调用我的函数plot()。这怎么可能？

Answer 1

您好，您的代码无法运行，我们需要 Minimal Reproducible Example ，至少我可以，除非这里有更好的人来处理它。尽管如此，我还是对你的问题很感兴趣，所以用谷歌搜索了一下，发现了很好的教程：https://www.pythonguis.com/tutorials/plotting-matplotlib/。

从那里我偷了一些代码来尝试重现一些关于 '在 PyQt5 中清除并重新填充 Matplotlib'。

看看我的代码，清除后别忘了canvas.draw()

import sys
import random
import matplotlib

matplotlib.use('Qt5Agg')

from PyQt5 import QtCore, QtWidgets

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure



def random_list(n , v):
        randomlist = []
        for i in range(0,n):
            add = random.randint(0,v)
            randomlist.append(add)
        print(randomlist)
        
        return randomlist   

class MplCanvas(FigureCanvas):

    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)
        super(MplCanvas, self).__init__(fig)


class MainWindow(QtWidgets.QMainWindow):

    def __init__(self, *args, **kwargs):
        
        self.deleted = ''
        
        super(MainWindow, self).__init__(*args, **kwargs)


        self.setGeometry(10,80,800,600)
        
        self.pushButton_1 = QtWidgets.QPushButton(self)
        self.pushButton_1.setGeometry(QtCore.QRect(600, 520, 150, 50))
        self.pushButton_1.setObjectName("pushButton_1")
        self.pushButton_1.setStyleSheet('background-color: red;')
        self.pushButton_1.setText('Re-Draw')
        
        self.pushButton_2 = QtWidgets.QPushButton(self)
        self.pushButton_2.setGeometry(QtCore.QRect(600, 450, 150, 50))
        self.pushButton_2.setObjectName("pushButton_2")
        self.pushButton_2.setStyleSheet('background-color: blue;')
        self.pushButton_2.setText('Clean_Cla')
        
        self.pushButton_3 = QtWidgets.QPushButton(self)
        self.pushButton_3.setGeometry(QtCore.QRect(400, 520, 150, 50))
        self.pushButton_3.setObjectName("pushButton_3")
        self.pushButton_3.setStyleSheet('background-color: yellow;')
        self.pushButton_3.setText('Rebuild')
        
        
        self.pushButton_1.clicked.connect(self.update_plot)
        
        self.pushButton_2.clicked.connect(self.clean_cla_plot)
        
        self.pushButton_3.clicked.connect(self.rebuild)
        
        self.canvas2 = MplCanvas(self, width=5, height=4, dpi=50)
        self.canvas2.setParent(self)
        self.canvas2.move(450,0)
        
        self.canvas3 = MplCanvas(self, width=5, height=4, dpi=50)
        self.canvas3.setParent(self)
        self.canvas3.move(450,200)
        
        self.canvas = MplCanvas(self, width=8, height=8, dpi=50)
        self.canvas.setParent(self)
        
        # self.setCentralWidget(self.canvas)


        self.xdata = random_list(20, 50)
        self.ydata = random_list(20, 50)
        self.update_plot()

        
        
        
        self.show()
        
        print('@@@@@@ : ',self.deleted, type(self.deleted))


    def update_plot(self):
        
        print('update', 'self.deleted : ', self.deleted)
        self.canvas.axes.cla()  # Clear the canvas.
        self.canvas.axes.scatter(random_list(20, 50), random_list(20, 50))
        # Trigger the canvas to update and redraw.
        self.canvas.draw()
        
        self.canvas2.axes.cla()  # Clear the canvas.
        self.canvas2.axes.scatter(random_list(20, 50), random_list(20, 50), c = 'red')
        # Trigger the canvas to update and redraw.
        self.canvas2.draw()
        self.canvas2.show()
        
        
        if self.deleted != 'yep' :
            self.canvas3.axes.cla()  # Clear the canvas.
            self.canvas3.axes.scatter(random_list(20, 50), random_list(20, 50), c = 'green')
            # Trigger the canvas to update and redraw.
            self.canvas3.draw()
            self.canvas3.show()
        
        
    def clean_cla_plot(self):
        
        print('clean')
        self.canvas.axes.cla()  # Clear the canvas.
        self.canvas2.axes.clear() 
        
        # Trigger the canvas to update and redraw.
        self.canvas.draw()
        self.canvas2.hide()   
        
        if self.deleted != 'yep':
            self.canvas3.deleteLater()
            self.deleted = 'yep'
            
    
    def rebuild(self):
        
        if self.deleted == 'yep' :
            # self.canvas3.cla()
            print(self.canvas3)
            self.canvas3 = MplCanvas(self, width=5, height=4, dpi=50)
            self.canvas3.setParent(self)
            self.canvas3.move(450,200)
            print(self.canvas3)
            self.deleted = 'nope' 
            print('rebbuild', 'self.deleted : ', self.deleted)

app = QtWidgets.QApplication(sys.argv)
w = MainWindow()
app.exec_()