利用PyQt5+Matplotlib 绘制静态/动态图

• 代码编辑环境
• 功能实现
• 效果展示
• 代码块（业务与逻辑分离）
• 业务--UI界面代码
• 逻辑--主要代码分析
• matplotlib作图嵌入PyQt界面的关键
• 初始图形显示设置
• 主界面的逻辑代码
• 几点说明
• 静态做图
• 动态做图
• 改进说明
• 最终完整代码

代码编辑环境

Win10+(Pycharmm or Vscode)+PyQt 5.14.2

功能实现

静态作图：数据作图，取决于作图函数，可自行修改
动态作图：产生数据，获取并更新数据，最后刷新显示，可用于实现数据实时采集并显示的场景

效果展示

代码块（业务与逻辑分离）

业务–UI界面代码

文件名：Ui_realtimer_plot.py

# -*- coding: utf-8 -*-
# Added by the Blog author VERtiCaL on 2020/07/12 at SSRF
# Created by: PyQt5 UI code generator 5.14.2
#
# WARNING! All changes made in this file will be lost!


from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1613, 1308)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.Plot_static = QtWidgets.QGroupBox(self.centralwidget)
        self.Plot_static.setGeometry(QtCore.QRect(260, 30, 861, 391))
        self.Plot_static.setObjectName("Plot_static")
        self.layoutWidget = QtWidgets.QWidget(self.centralwidget)
        self.layoutWidget.setGeometry(QtCore.QRect(300, 830, 701, 91))
        self.layoutWidget.setObjectName("layoutWidget")
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.layoutWidget)
        self.horizontalLayout.setContentsMargins(0, 0, 0, 0)
        self.horizontalLayout.setSpacing(28)
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.Static_plot = QtWidgets.QPushButton(self.layoutWidget)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.MinimumExpanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.Static_plot.sizePolicy().hasHeightForWidth())
        self.Static_plot.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily("楷体")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.Static_plot.setFont(font)
        self.Static_plot.setObjectName("Static_plot")
        self.horizontalLayout.addWidget(self.Static_plot)
        self.dynamic_plot = QtWidgets.QPushButton(self.layoutWidget)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.MinimumExpanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.dynamic_plot.sizePolicy().hasHeightForWidth())
        self.dynamic_plot.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily("楷体")
        font.setPointSize(18)
        font.setBold(False)
        font.setWeight(50)
        self.dynamic_plot.setFont(font)
        self.dynamic_plot.setObjectName("dynamic_plot")
        self.horizontalLayout.addWidget(self.dynamic_plot)
        self.End_plot = QtWidgets.QPushButton(self.layoutWidget)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.MinimumExpanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.End_plot.sizePolicy().hasHeightForWidth())
        self.End_plot.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily("楷体")
        font.setPointSize(18)
        self.End_plot.setFont(font)
        self.End_plot.setObjectName("End_plot")
        self.horizontalLayout.addWidget(self.End_plot)
        self.Erase_plot = QtWidgets.QPushButton(self.layoutWidget)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.MinimumExpanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.Erase_plot.sizePolicy().hasHeightForWidth())
        self.Erase_plot.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setFamily("楷体")
        font.setPointSize(18)
        self.Erase_plot.setFont(font)
        self.Erase_plot.setObjectName("Erase_plot")
        self.horizontalLayout.addWidget(self.Erase_plot)
        self.Plot_dynamic = QtWidgets.QGroupBox(self.centralwidget)
        self.Plot_dynamic.setGeometry(QtCore.QRect(260, 430, 861, 391))
        self.Plot_dynamic.setObjectName("Plot_dynamic")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 1613, 23))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.Plot_static.setTitle(_translate("MainWindow", "StaticPlot"))
        self.Static_plot.setText(_translate("MainWindow", "静态作图"))
        self.dynamic_plot.setText(_translate("MainWindow", "动态作图"))
        self.End_plot.setText(_translate("MainWindow", "停止作图"))
        self.Erase_plot.setText(_translate("MainWindow", "清除数据"))
        self.Plot_dynamic.setTitle(_translate("MainWindow", "DynamicPlot"))

逻辑–主要代码分析

matplotlib作图嵌入PyQt界面的关键

创建matlibplot图形类Myplot，通过继承FigureCanvas类，使其相当于PyQt里的控件，从而完成PyQt与Matlibplot的结合。

# class Myplot for plotting with matplotlib
class Myplot(FigureCanvas):
    def __init__(self, parent=None, width=5, height=3, dpi=100):
        # normalized for 中文显示和负号
        plt.rcParams['font.sans-serif'] = ['SimHei']
        plt.rcParams['axes.unicode_minus'] = False

        # new fig
        self.fig = Figure(figsize=(width, height), dpi=dpi)
        # activate figure window
        # super(Plot_dynamic,self).__init__(self.fig)
        FigureCanvas.__init__(self, self.fig)
        self.setParent(parent)
        # sub plot by self.axes
        self.axes= self.fig.add_subplot(111)
        # initial figure
        self.compute_initial_figure()

        # size policy
        FigureCanvas.setSizePolicy(self,
                                   QtWidgets.QSizePolicy.Expanding,
                                   QtWidgets.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

    def compute_initial_figure(self):
        pass

初始图形显示设置

用于图形初始化的图像类，通过调用这个类就能实现图形绘制和修改。可以在此更改图形的类型，具体代码可以参照matplotlib官网的实例 Matplotlib_examples

class static_fig(Myplot):
    def __init__(self,*args,**kwargs):
        Myplot.__init__(self,*args,**kwargs)

    def compute_initial_figure(self):
        x=np.linspace(0,2*np.pi,100)
        y=x*np.sin(x)
        self.axes.plot(x,y)
        self.axes.set_title("signals")
        self.axes.set_xlabel("delay(s)")
        self.axes.set_ylabel("counts")

主界面的逻辑代码

几点说明

1、利用Matplotlib自带的NavigationToolbar可以实现绘制图的基本操作：平移、放大、保存图像、显示鼠标位置（x，y）的数据等
2、self.gridlayout1.addWidget(self.fig1)就是把绘制的图像本身作为一个控件widget加入UI界面里的groupbox（这里改成Plot_static名称）去，从而使得图形能正常显示在绘图框里。

class AppWindow(QMainWindow,Ui_MainWindow):
    def __init__(self,parent=None):
        super(AppWindow,self).__init__(parent)
        self.setupUi(self)
        # ^O^ static_fig can changed to any other function
        #self.fig1=static_fig(width=5, height=4, dpi=100)
        self.fig1 = static_fig(width=5, height=3, dpi=72)
        self.fig2 = dynamic_fig(width=5, height=3, dpi=72)
        # add NavigationToolbar in the figure (widgets)
        self.fig_ntb1 = NavigationToolbar(self.fig1, self)
        self.fig_ntb2 = NavigationToolbar(self.fig2, self)
        #self.Start_plot.clicked.connect(self.plot_cos)
        # add the static_fig in the Plot box
        self.gridlayout1=QGridLayout(self.Plot_static)
        self.gridlayout1.addWidget(self.fig1)
        self.gridlayout1.addWidget(self.fig_ntb1)
        # add the dynamic_fig in the Plot box
        self.gridlayout2 = QGridLayout(self.Plot_dynamic)
        self.gridlayout2.addWidget(self.fig2)
        self.gridlayout2.addWidget(self.fig_ntb2)
        self._timer = QTimer(self)
        self._t = 1
        self._counts = []
        self._delay_t = []

静态做图

self.fig1.axes.cla()清除原来的图像，self.fig1.axes.plot(self.t,self.y)，通过self.fig1.axes.plot实现做图，不同类型的图形做图参考matplotlib官网。 Matplotlib_examples

@pyqtSlot()
    def on_Static_plot_clicked(self):
        self.plot_cos()
        self._Static_on=1
        #self.Start_plot.setEnabled(False)

    global nc
    nc=1
    def plot_cos(self):
        #print('nc=%d\n' %self.nc)
        global nc
        nc+=1
        self.fig1.axes.cla()
        self.t=np.arange(0,15,0.1)
        self.y=2*nc*self.t-self.t*np.cos(self.t/2/np.pi*1000)
        self.fig1.axes.plot(self.t,self.y)
        self.fig1.axes.set_title("signals",fontsize=18,color='c')
        self.fig1.axes.set_xlabel("delay(s)",fontsize=18,color='c')
        self.fig1.axes.set_ylabel("counts",fontsize=18,color='c')
        self.fig1.draw()

动态做图

这里数据接收通过QTimer来延迟时间（隔1s）并通过函数产生计数，append更新数据，做图，刷新图像，self.fig2.draw()实现图像绘制。

@pyqtSlot()
    def on_dynamic_plot_clicked(self):
        print('start dynamic ploting')
        self.Static_plot.setEnabled(False)
        self.dynamic_plot.setEnabled(False)
        # start update figure every 1s; flag "update_on" : 1 is on and 0 is Off
        self._update_on = 1
        self._timer.timeout.connect(self.update_fig)
        self._timer.start(1000)  # plot after 1s delay

    def update_fig(self):
        self._t+=1
        print(self._t)
        self._delay_t.append(self._t)
        print(self._delay_t)
        #new_counts=random.randint(100,900)
        new_counts= 2 * self._t - self._t * np.cos(self._t / 2 / np.pi * 1000)
        self._counts.append(new_counts)
        print(self._counts)
        self.fig2.axes.cla()
        self.fig2.axes.plot(self._delay_t,self._counts,'-ob')
        self.fig2.axes.set_title("signals",fontsize=18,color='c')
        self.fig2.axes.set_xlabel("delay(s)",fontsize=18,color='c')
        self.fig2.axes.set_ylabel("counts",fontsize=18,color='c')
        self.fig2.draw()

改进说明

后续可以通过引入多线程，单独进行数据采集、显示和保存，完善功能。

最终完整代码

# -*- coding: utf-8 -*-

""" Module: plot data realtime. Created on 2020/07/12 by Blog Author VERtiCaL at SSRF """

import matplotlib
matplotlib.use("Qt5Agg")
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5 import NavigationToolbar2QT as NavigationToolbar
from PyQt5 import QtCore, QtWidgets
from PyQt5.QtWidgets import QWidget, QPushButton, QApplication,QMainWindow,QGridLayout
from PyQt5.QtCore import QTimer,pyqtSlot,QThread
from matplotlib.figure import Figure
import matplotlib.pyplot as plt
import numpy as np
import sys,random, time,os,re
from Ui_Realtimer_Plot import Ui_MainWindow


# class Myplot for plotting with matplotlib
class Myplot(FigureCanvas):
    def __init__(self, parent=None, width=5, height=3, dpi=100):
        # normalized for 中文显示和负号
        plt.rcParams['font.sans-serif'] = ['SimHei']
        plt.rcParams['axes.unicode_minus'] = False

        # new figure
        self.fig = Figure(figsize=(width, height), dpi=dpi)
        # activate figure window
        # super(Plot_dynamic,self).__init__(self.fig)
        FigureCanvas.__init__(self, self.fig)
        self.setParent(parent)
        #self.fig.canvas.mpl_connect('button_press_event', self)
        # sub plot by self.axes
        self.axes= self.fig.add_subplot(111)
        # initial figure
        self.compute_initial_figure()

        # size policy
        FigureCanvas.setSizePolicy(self,
                                   QtWidgets.QSizePolicy.Expanding,
                                   QtWidgets.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

    def compute_initial_figure(self):
        pass



# class for plotting a specific figure static or dynamic
class static_fig(Myplot):
    def __init__(self,*args,**kwargs):
        Myplot.__init__(self,*args,**kwargs)

    def compute_initial_figure(self):
        x=np.linspace(0,2*np.pi,100)
        y=x*np.sin(x)
        self.axes.plot(x,y)
        self.axes.set_title("signals")
        self.axes.set_xlabel("delay(s)")
        self.axes.set_ylabel("counts")


class dynamic_fig(Myplot):
    def __init__(self,*args,**kwargs):
        Myplot.__init__(self,*args,**kwargs)

    def compute_initial_figure(self):
        counts = [1,10]
        delay_t = [0,1]
        self.axes.plot(delay_t,counts,'-ob')
        self.axes.set_title("signals")
        self.axes.set_xlabel("delay(s)")
        self.axes.set_ylabel("counts")



# class for the application window
class AppWindow(QMainWindow,Ui_MainWindow):
    def __init__(self,parent=None):
        super(AppWindow,self).__init__(parent)
        self.setupUi(self)
        # ^O^ static_fig can changed to any other function
        #self.fig1=static_fig(width=5, height=4, dpi=100)
        self.fig1 = static_fig(width=5, height=3, dpi=72)
        self.fig2 = dynamic_fig(width=5, height=3, dpi=72)
        # add NavigationToolbar in the figure (widgets)
        self.fig_ntb1 = NavigationToolbar(self.fig1, self)
        self.fig_ntb2 = NavigationToolbar(self.fig2, self)
        #self.Start_plot.clicked.connect(self.plot_cos)
        # add the static_fig in the Plot box
        self.gridlayout1=QGridLayout(self.Plot_static)
        self.gridlayout1.addWidget(self.fig1)
        self.gridlayout1.addWidget(self.fig_ntb1)
        # add the dynamic_fig in the Plot box
        self.gridlayout2 = QGridLayout(self.Plot_dynamic)
        self.gridlayout2.addWidget(self.fig2)
        self.gridlayout2.addWidget(self.fig_ntb2)
        # initialized flags for static/dynamic plot: on is 1,off is 0
        self._timer = QTimer(self)
        self._t = 1
        self._counts = []
        self._delay_t = []
        self._Static_on=0
        self._update_on=0



    @pyqtSlot()
    def on_Static_plot_clicked(self):
        self.plot_cos()
        self._Static_on=1
        #self.Start_plot.setEnabled(False)

    global nc
    nc=1
    def plot_cos(self):
        #print('nc=%d\n' %self.nc)
        global nc
        nc+=1
        self.fig1.axes.cla()
        self.t=np.arange(0,15,0.1)
        self.y=2*nc*self.t-self.t*np.cos(self.t/2/np.pi*1000)
        self.fig1.axes.plot(self.t,self.y)
        self.fig1.axes.set_title("signals",fontsize=18,color='c')
        self.fig1.axes.set_xlabel("delay(s)",fontsize=18,color='c')
        self.fig1.axes.set_ylabel("counts",fontsize=18,color='c')
        self.fig1.draw()

    @pyqtSlot()
    def on_dynamic_plot_clicked(self):
        print('start dynamic ploting')
        self.Static_plot.setEnabled(False)
        self.dynamic_plot.setEnabled(False)
        # start update figure every 1s; flag "update_on" : 1 is on and 0 is Off
        self._update_on = 1
        self._timer.timeout.connect(self.update_fig)
        self._timer.start(1000)  # plot after 1s delay

    
    
    def update_fig(self):
        self._t+=1
        print(self._t)
        self._delay_t.append(self._t)
        print(self._delay_t)
        #new_counts=random.randint(100,900)
        new_counts= 2 * self._t - self._t * np.cos(self._t / 2 / np.pi * 1000)
        self._counts.append(new_counts)
        print(self._counts)
        self.fig2.axes.cla()
        self.fig2.axes.plot(self._delay_t,self._counts,'-ob')
        self.fig2.axes.set_title("signals",fontsize=18,color='c')
        self.fig2.axes.set_xlabel("delay(s)",fontsize=18,color='c')
        self.fig2.axes.set_ylabel("counts",fontsize=18,color='c')
        self.fig2.draw()

    @pyqtSlot()
    def on_End_plot_clicked(self):
        if self._update_on==1:
            self._update_on=0
            self._timer.timeout.disconnect(self.update_fig)
            self.dynamic_plot.setEnabled(True)
        else:
            pass

    @pyqtSlot()
    def on_Erase_plot_clicked(self):
        self.fig1.axes.cla()
        self.fig1.draw()
        self.fig2.axes.cla()
        self.fig2.draw()
        if  self._update_on==1:
            self._update_on=0
            self._delay_t=[]
            self._counts=[]
            self.fig2.axes.cla()
            self.fig2.draw()
            self._timer.timeout.disconnect(self.update_fig)
            self.dynamic_plot.setEnabled(True)
        else:
            pass
        self.Static_plot.setEnabled(True)
        #self.Erase_plot.setEnabled(False)
    

if __name__=="__main__":
    app = QApplication(sys.argv)
    win = AppWindow()
    win.show()
    sys.exit(app.exec_())