pyqt5でのmatplotlibによるグラフ表示がうまくいかない

python3.5を使っています。pyqt5でmatplotlibを使ってみたところ、matplotlibで使えていた一部の機能が使えなくなりました。具体的にはx、y軸のラベル、グラフのタイトルが表示されないほか、x、y軸の表示範囲設定ができなりました。コードをどのように直せばよいのでしょうか。

import sys
from PyQt5 import QtWidgets
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5 import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt

import random
import numpy as np


class Window(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.setWindowTitle("グラフ")
        self.setGeometry(300,300,500,500)

        self.figure = plt.figure()
        self.axes = self.figure.add_subplot(111)
        # We want the axes cleared every time plot() is called
        self.axes.hold(False)
        self.canvas = FigureCanvas(self.figure)
        self.canvas.move(0,0)


        self.toolbar = NavigationToolbar(self.canvas, self)
        self.toolbar.hide()

        # Just some button 
        self.button1 = QtWidgets.QPushButton('Plot',self)
        self.button1.clicked.connect(self.plot)
        self.button1.move(0,400)

        self.button2 = QtWidgets.QPushButton('Zoom',self)
        self.button2.clicked.connect(self.zoom)
        self.button2.move(100,400)

        self.button3 = QtWidgets.QPushButton('Pan',self)
        self.button3.clicked.connect(self.pan)
        self.button3.move(200,400)

        self.button4 = QtWidgets.QPushButton('Home',self)
        self.button4.clicked.connect(self.home)
        self.button4.move(300,400)

        self.grid_cb = QCheckBox("Show &Grid")
        self.grid_cb.setChecked(False)
        self.grid_cb.stateChanged.connect(self.plot) #int

        # set the layout
        layout = QtWidgets.QVBoxLayout()
        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        layout.addWidget(self.grid_cb)


        btnlayout = QtWidgets.QHBoxLayout()
        btnlayout.addWidget(self.button1)
        btnlayout.addWidget(self.button2)
        btnlayout.addWidget(self.button3)
        btnlayout.addWidget(self.button4)
        #btnlayout.addWidget(self.grid_cb)
        qw = QtWidgets.QWidget(self)
        qw.setLayout(btnlayout)
        layout.addWidget(qw)

        self.setLayout(layout)

    def home(self):
        self.toolbar.home()
    def zoom(self):
        self.toolbar.zoom()
    def pan(self):
        self.toolbar.pan()

    def plot(self):

        x  = np.arange(0, 4*np.pi, 0.1)
        y=np.sin(x)
        self.axes.set_xlim(0,5)
        self.axes.set_ylim(-1.2,1.2)
        self.axes.set_xlabel("angle")
        self.axes.set_ylabel("intensity")
        self.axes.set_title("E")
        self.axes.plot(x,y,c="r")
        self.axes.grid(self.grid_cb.isChecked())
        self.canvas.draw()

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)

    main = Window()
    main.setWindowTitle('Simple QTpy and MatplotLib example with Zoom/Pan')
    main.show()

    sys.exit(app.exec_())