我有一个奇怪的问题，matplotlib。如果我运行这个程序，我可以打开和关闭几次相同的数字。

import numpy
from pylab import figure, show
X = numpy.random.rand(100, 1000)
xs = numpy.mean(X, axis=1)
ys = numpy.std(X, axis=1)
fig = figure()
ax = fig.add_subplot(111)
ax.set_title('click on point to plot time series')
line, = ax.plot(xs, ys, 'o', picker=5)  # 5 points tolerance
def onpick(event):
    figi = figure()
    ax = figi.add_subplot(111)
    ax.plot([1,2,3,4])        
    figi.show()
fig.canvas.mpl_connect('pick_event', onpick)
show()

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相反，如果我在我的自定义小部件中使用相同的onpick函数代码，它只会在第一次打开图形，在其他事件中，它会进入函数，但不会显示图形：

from PyQt4 import QtGui, QtCore
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt4 import NavigationToolbar2QT as NavigationToolbar
import time
STEP = 0.000152 
class MplCanvas(FigureCanvas):
    def __init__(self):
        # initialization of the canvas
        FigureCanvas.__init__(self, Figure())
        self.queue = []
        self.I_data = np.array([])
        self.T_data = np.array([])
        self.LvsT = self.figure.add_subplot(111)
        self.LvsT.set_xlabel('Time, s')
        self.LvsT.set_ylabel('PMT Voltage, V')
        self.LvsT.set_title("Light vs Time")
        self.LvsT.grid(True)
        self.old_size = self.LvsT.bbox.width, self.LvsT.bbox.height
        self.LvsT_background = self.copy_from_bbox(self.LvsT.bbox)
        self.LvsT_plot, = self.LvsT.plot(self.T_data,self.I_data)
        #self.LvsT_plot2, = self.LvsT.plot(self.T_data2,self.I_data2) 
        self.mpl_connect('axes_enter_event', self.enter_axes)
        self.mpl_connect('button_press_event', self.onpick)
        self.count = 0
        self.draw()
    def enter_axes(self,event):
        print "dentro"
    def onpick(self,event):
        print "click"
        print 'you pressed', event.canvas
        a = np.arange(10)
        print a
        print self.count
        fig = plt.figure()
        ax = fig.add_subplot(111)
        ax.plot(a)    
        fig.show()
    def Start_Plot(self,q,Vmin,Vmax,ScanRate,Cycles):
        self.queue = q
        self.LvsT.clear()
        self.LvsT.set_xlim(0,abs(Vmin-Vmax)/ScanRate*Cycles)
        self.LvsT.set_ylim(-3, 3)
        self.LvsT.set_autoscale_on(False)
        self.LvsT.clear()
        self.draw()
        self.T_data = np.array([])
        self.I_data = np.array([])
        # call the update method (to speed-up visualization)
        self.timerEvent(None)
        # start timer, trigger event every 1000 millisecs (=1sec)
        self.timerLvsT = self.startTimer(3)
    def timerEvent(self, evt):
        current_size = self.LvsT.bbox.width, self.LvsT.bbox.height
        if self.old_size != current_size:
            self.old_size = current_size
            self.LvsT.clear()
            self.LvsT.grid()
            self.draw()
            self.LvsT_background = self.copy_from_bbox(self.LvsT.bbox)
        self.restore_region(self.LvsT_background, bbox=self.LvsT.bbox)
        result = self.queue.get()
        if result == 'STOP': 
            self.LvsT.draw_artist(self.LvsT_plot)
            self.killTimer(self.timerLvsT)
            print "Plot finito LvsT"
        else:
            # append new data to the datasets
            self.T_data = np.append(self.T_data,result[0:len(result)/2])
            self.I_data = np.append(self.I_data,result[len(result)/2:len(result)])
            self.LvsT_plot.set_data(self.T_data,self.I_data)#L_data
            #self.LvsT_plot2.set_data(self.T_data2,self.I_data2)#L_data
            self.LvsT.draw_artist(self.LvsT_plot)
            self.blit(self.LvsT.bbox)
class LvsT_MplWidget(QtGui.QWidget):
    def __init__(self, parent = None):
        QtGui.QWidget.__init__(self, parent)        
        self.canvas = MplCanvas()
        self.vbl = QtGui.QVBoxLayout()
        self.vbl.addWidget(self.canvas)
        self.setLayout(self.vbl)

型
这个小部件是动画绘图所需的，当实验完成时，如果我点击绘图，它应该会出现一个图形，只会在第一次出现。
你有什么线索吗？
非常感谢