matplotlib作为Python中著名的数据可视化工具，其官网也提供了在PyQt4中使用的源码，这里举一个应用实例，以备不时之需。

1) 利用Qt Designer创建GUI界面

Demo的GUI界面，如图1所示，其中利用QFrame作为放置matplotlib界面的容器。然后调用pyuic4.bat -o ui_maindialog.py maindialog.ui编译UI界面。

图1 GUI设计界面

2) maindialog.py程序代码

#!/usr/bin/env python#-*- coding: utf-8 -*-import numpy as npfrom PyQt4.QtCore import *from PyQt4.QtGui import *from ui_maindialog import Ui_MainDialogfrom matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas # matplotlib对PyQt4的支持from matplotlib.figure import Figureclass MainDialog(QDialog, Ui_MainDialog):    def __init__(self, parent=None):        super(MainDialog, self).__init__(parent)        self.setupUi(self)        self._createFigures()        self._createLayouts() 　　# 创建matplotlib的画布    def _createFigures(self):        self._fig = Figure(figsize=(8, 6), dpi=100, tight_layout=True)         self._fig.set_facecolor("#F5F5F5") # 背景色        self._fig.subplots_adjust(left=0.08, top=0.92, right=0.95, bottom=0.1) # Margins        self._canvas = FigureCanvas(self._fig) # 画布        self._ax = self._fig.add_subplot(111) # 增加subplot        self._ax.hold(True)        self._initializeFigure()    def _createLayouts(self):        layout = QHBoxLayout(self.frame)        layout.setContentsMargins(0, 0, 0, 0)        layout.addWidget(self._canvas) # Add Matplotli    def _initializeFigure(self):        Font = {
   'family': 'Tahoma',                'weight': 'bold',                'size': 10}        # Abscissa        self._ax.set_xlim([380, 780])        self._ax.set_xticks([380, 460, 540, 620, 700, 780])        self._ax.set_xticklabels([380, 460, 540, 620, 700, 780], fontdict=Font)        self._ax.set_xlabel("Wavelength (nm)", fontdict=Font)        # Ordinate        self._ax.set_ylim([0.0, 1.0])        self._ax.set_yticks(np.arange(0.0, 1.1, 0.2))        self._ax.set_yticklabels(np.arange(0.0, 1.1, 0.2), fontdict=Font)        self._ax.set_ylabel("Spectral Radiance (W/(m$^2$*sr*nm))", fontdict=Font)        self._ax.grid(True)  # Grid On    def _updateFigures(self):        Font = {
   'family': 'Tahoma',                'weight': 'bold',                'size': 10}        self._ax.clear()        maxY = 0.0        x = np.arange(380, 781)        y = np.random.rand(401)        self._ax.plot(x, y, 'r', label="Data") 　　　　 maxY = max(y)        if maxY <= 0:            self._initializeFigure()        else:            self._fig.subplots_adjust(left=0.11, top=0.92, right=0.95, bottom=0.1)            # Abscissa            self._ax.set_xlim([380, 780])            self._ax.set_xticks([380, 460, 540, 620, 700, 780])            self._ax.set_xticklabels([380, 460, 540, 620, 700, 780], fontdict=Font)            self._ax.set_xlabel("Wavelength (nm)", fontdict=Font)            # Ordinate            self._ax.set_ylim([0.0, maxY])            self._ax.set_yticks([0.0, maxY / 4.0, maxY / 2.0, maxY * 3 / 4.0, maxY])            self._ax.set_yticklabels(                ["%.1e" % 0.0, "%.1e" % (maxY / 4.0), "%.1e" % (maxY / 2.0), "%.1e" % (maxY * 3.0 / 4.0),                 "%.1e" % maxY], fontdict=Font)            self._ax.set_ylabel("Spectral Radiance (W/(m$^2$*sr*nm))", fontdict=Font)        self._ax.grid(True)        self._ax.legend(loc="best", fontsize="small").draggable(state=True)  # Legend        self._canvas.draw()    @pyqtSlot()    def on_plotPushButton_clicked(self):        self._updateFigures()

初始界面如图2所示：

图2 GUI初始界面

3) 点击plot按键后

界面显示见图3：

 

图3 点击Plot按键后界面