在pyqt5中使用matplotlib

前言

虽然，qt中也提供了绘图函数，但对于初学者并不是很容易掌握，众所周知，matplot提供了简单，易用，强大的绘图函数，结合mumpy基本可以达到matlb中的绘图体验，并且比matlab更加具有扩展性，也更自由。通过matplotlib提供的官方例程的修改，就可以很容易的绘制你想要的图形，真的很强大。（我也是名初学者）

matplotlib，pyqt5官方例程

# 取自matplotlib 官方文档案例from __future__ import unicode_literals
import sys
import os
import random
import matplotlib
# Make sure that we are using QT5
matplotlib.use('Qt5Agg')from PyQt5 import QtCore, QtWidgets
from numpy import arange, sin, pi, linspace
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figureprogname = os.path.basename(sys.argv[0])
progversion = "0.1"class MyMplCanvas(FigureCanvas):# 这既是一个wiget类也是一个FigureCanvadef __init__(self, parent=None, width=5, height=4, dpi=100):self.fig = Figure(figsize=(width, height), dpi=dpi)self.axes = self.fig.add_subplot(111)self.compute_initial_figure()FigureCanvas.__init__(self, self.fig)self.setParent(parent)FigureCanvas.setSizePolicy(self,QtWidgets.QSizePolicy.Expanding,QtWidgets.QSizePolicy.Expanding)FigureCanvas.updateGeometry(self)def compute_initial_figure(self):passclass MyStaticMplCanvas(MyMplCanvas):"""Simple canvas with a sine plot."""def __init__(self, *args, **kwargs):MyMplCanvas.__init__(self, *args, **kwargs)def compute_initial_figure(self):print("hello world")x = linspace(0, 2 * pi, 500000)y = sin(x)self.axes.cla()self.axes.plot(x, y)self.draw()class MyDynamicMplCanvas(MyMplCanvas):"""A canvas that updates itself every second with a new plot."""def __init__(self, *args, **kwargs):MyMplCanvas.__init__(self, *args, **kwargs)timer = QtCore.QTimer(self)timer.timeout.connect(self.update_figure)timer.start(1000)def compute_initial_figure(self):self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'r')def update_figure(self):# Build a list of 4 random integers between 0 and 10 (both inclusive)l = [random.randint(0, 10) for i in range(4)]self.axes.cla()self.axes.plot([0, 1, 2, 3], l, 'r')self.draw()class ApplicationWindow(QtWidgets.QMainWindow):def __init__(self):QtWidgets.QMainWindow.__init__(self)self.setAttribute(QtCore.Qt.WA_DeleteOnClose)self.setWindowTitle("application main window")self.file_menu = QtWidgets.QMenu('&File', self)self.file_menu.addAction('&Quit', self.fileQuit,QtCore.Qt.CTRL + QtCore.Qt.Key_Q)self.menuBar().addMenu(self.file_menu)self.help_menu = QtWidgets.QMenu('&Help', self)self.menuBar().addSeparator()self.menuBar().addMenu(self.help_menu)self.help_menu.addAction('&About', self.about)self.main_widget = QtWidgets.QWidget(self)l = QtWidgets.QVBoxLayout(self.main_widget)sc = MyStaticMplCanvas(self.main_widget, width=5, height=4, dpi=100)dc = MyDynamicMplCanvas(self.main_widget, width=5, height=4, dpi=100)l.addWidget(sc)l.addWidget(dc)self.main_widget.setFocus()self.setCentralWidget(self.main_widget)self.statusBar().showMessage("All hail matplotlib!", 2000)def fileQuit(self):self.close()def closeEvent(self, ce):self.fileQuit()def about(self):QtWidgets.QMessageBox.about(self, "About","""embedding_in_qt5.py example
Copyright 2005 Florent Rougon, 2006 Darren Dale, 2015 Jens H NielsenThis program is a simple example of a Qt5 application embedding matplotlib
canvases.It may be used and modified with no restriction; raw copies as well as
modified versions may be distributed without limitation.This is modified from the embedding in qt4 example to show the difference
between qt4 and qt5""")

代码解析

通过matplotlib.use('Qt5Agg')，这行代码声明matplotlib将要嵌入到pyqt5中，同样通过这句，也可以声明将matplotlib嵌入到其他的，gui界面中去，然后通过继承FigureCanvas类来获得一个即使widget的类也是FigureCanva类的类，然后通过self.fig成员，生成一个绘图类，并由其创建一个绘图布局，返回一个self.axes来管理绘图布局中的内容。坐标轴，标题，标签，图形样式（饼图，柱状图，折线图等）等等的设置都通过self.axes的成员函数来设置完成。刚开始的使用还是比较云里雾里的，现在就差不多了。我对官方例程做了些修改，具体的代码，可以到我的GitHub仓储上查看Qt-learn-pyqt5-matplotlib里面也有一些其他的例子，应该还会不定期的更新，有兴趣也可以看看。下面只需要对这几个类进行实例话，开启qt的事件循环就可以看到界面了，具体的可以看我的github代码，这里就不多说了。

写在最后

因为自身能力有限，也不是科班出身，都是自学的，目前还是一名学生，所以有未尽之处还请指正，不喜勿喷。谢谢。