清除PyQ中的matplotlib绘图

Question

我的代码打开一个PyQt窗口，其中包含matplotlib图。顶部有10个按钮，每个按钮都有自己的数据值来绘制。我想知道如何清除当前显示的上一个绘图，然后在单击按钮时绘制新的绘图。在

我使用PyQt4和python3。在

import pandas as pd
import matplotlib.pyplot as plt
import numpy as np
import scipy.io
import sys
import os
from matplotlib.backends.backend_qt4agg import (FigureCanvasQTAgg as FigureCanvas)
from matplotlib.figure import Figure
from PyQt4.QtGui import *
from PyQt4 import QtCore

plt.style.use('ggplot')

def Extract_Data(name):

    #setting up lists

    Stim_trig = []
    Stim_order = []
    Sch_wav = []

    data = scipy.io.loadmat(name)

    for k,v in data.items():

        #Sends Sch_wav data to a list
        if "Sch_wav" in k:

            for d in (((v[0])[0])[4]):
                Sch_wav.append(d[0])

        #Sends StimTrig to a list
        if k=="StimTrig":
            for g in (((v[0])[0])[4]):
                Stim_trig.append(g[0])
            Stim_trig.append(Stim_trig[-1]+1)

        #Sends Stim order to a list

            for w in (((v[0])[0])[5]):
                Stim_order.append(w[0])

    superdata = []

    #Prepares grouping stimuli and trigger

    for i in range(len(Stim_trig)-1):
        fire = []
        for p in Sch_wav:
            if p > Stim_trig[i] and p < Stim_trig[i+1]:
                fire.append(p - Stim_trig[i])
        superdata.append([Stim_order[i],fire])


    #sorts all the data
    superdata.sort()

    alladdedup = [[1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[62]]
    count = 0
    for d in superdata:
        if d[0] == (alladdedup[count])[0]:
            for j in d[1]:
                ((alladdedup)[count]).append(j)
        else:
            count += 1
    #places time stamps of triggers in lists for each trigger

    for l in alladdedup:
        l.pop(0)
        l.sort()
        #removes title and sorts data

    ffmsb = []

    #finds number of firings for each milisecond bin
    for v in alladdedup:
        fmsb = []

        for b in range(1000):
            msbc = b/1000
            msb = []

            for t in v:
                if t > msbc and t < msbc + 0.001:
                    msb.append(t)

            fmsb.append(len(msb))

        ffmsb.append(fmsb)
    #returns list of stimuli firings per milisecond bin
    return(ffmsb)

class DisplayWidget(QMainWindow):
    def __init__(self, parent=None):
        super(DisplayWidget, self).__init__( parent )

        self.initUI()

    def initUI(self):

        self.main_frame = QWidget()

        self.canvas = PlotCanvas(self)
        self.canvas.setParent(self.main_frame)

        self.one = QPushButton('Intensity 1')
        self.two = QPushButton('Intensity 2')
        self.three = QPushButton('Intensity 3')
        self.four = QPushButton('Intensity 4')
        self.five = QPushButton('Intensity 5')
        self.six = QPushButton('Intensity 6')
        self.seven = QPushButton('Intensity 7')
        self.eight = QPushButton('Intensity 8')
        self.nine = QPushButton('Intensity 9')
        self.ten = QPushButton('Intensity 10')

        self.one.connect(self.one, QtCore.SIGNAL('clicked()'), self.setIntensity_one)
        self.two.connect(self.two, QtCore.SIGNAL('clicked()'), self.setIntensity_two)
        self.three.connect(self.three, QtCore.SIGNAL('clicked()'), self.setIntensity_three)
        self.four.connect(self.four, QtCore.SIGNAL('clicked()'), self.setIntensity_four)
        self.five.connect(self.five, QtCore.SIGNAL('clicked()'), self.setIntensity_five)
        self.six.connect(self.six, QtCore.SIGNAL('clicked()'), self.setIntensity_six)
        self.seven.connect(self.seven, QtCore.SIGNAL('clicked()'), self.setIntensity_seven)
        self.eight.connect(self.eight, QtCore.SIGNAL('clicked()'), self.setIntensity_eight)
        self.nine.connect(self.nine, QtCore.SIGNAL('clicked()'), self.setIntensity_nine)
        self.ten.connect(self.ten, QtCore.SIGNAL('clicked()'), self.setIntensity_ten)

        grid = QGridLayout()
        grid.addWidget(self.canvas, 1, 0, 10, 10)  # the matplotlib canvas
        grid.addWidget(self.one, 0, 0)
        grid.addWidget(self.two, 0, 1)
        grid.addWidget(self.three, 0, 2)
        grid.addWidget(self.four, 0, 3)
        grid.addWidget(self.five, 0, 4)
        grid.addWidget(self.six, 0, 5)
        grid.addWidget(self.seven, 0, 6)
        grid.addWidget(self.eight, 0, 7)
        grid.addWidget(self.nine, 0, 8)
        grid.addWidget(self.ten, 0, 9)



        self.main_frame.setLayout(grid)
        self.setCentralWidget(self.main_frame)
        self.setWindowTitle('Neurons')

        self.showMaximized()

    def setIntensity_one(self):
        self.data(intensity = 1)

    def setIntensity_two(self):
        self.data(intensity = 2)

    def setIntensity_three(self):
        self.data(intensity = 3)

    def setIntensity_four(self):
        self.data(intensity = 4)

    def setIntensity_five(self):
        self.data(intensity = 5)

    def setIntensity_six(self):
        self.data(intensity = 6)

    def setIntensity_seven(self):
        self.data(intensity = 7)

    def setIntensity_eight(self):
        self.data(intensity = 8)

    def setIntensity_nine(self):
        self.data(intensity = 9)

    def setIntensity_ten(self):
        self.data(intensity = 10)


    def data(self, intensity):
        stimuli = (Extract_Data("654508_rec02_all.mat")[intensity])

        numberlist = []
        for i in range(1000):
            numberlist.append(i/1000)

        d = pd.Series(stimuli, index = numberlist)
        self.df = pd.DataFrame(d)
        self.canvas.plot_data_frame(self.df)

class PlotCanvas(FigureCanvas, DisplayWidget):
    def __init__(self, parent = None, width = 12, height = 9):
        self.fig = Figure(figsize = (width, height))
        self.axes = self.fig.add_subplot(111)


        FigureCanvas.__init__(self, self.fig)
        self.setParent(parent)

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


    def plot_data_frame(self, df):

        df.plot( ax = self.axes,
            kind = 'line',
            title = 'Number of neurons firing',
            legend = False,
            xlim = (0, 1))
        self.draw()        

if __name__ == "__main__":

    app = QApplication( [] )
    widget = DisplayWidget()
    widget.show()
    app.exec_()

Answer 1

只需在plot_data_frame函数的每个绘图之前调用self.axes.cla()。这样可以清除轴。在