Question

我试图在Matplotlib中绘制同一轴上的线和数据点。当我尝试首先绘制线时，数据点被清除，当我尝试首先绘制数据点时也是如此。这是最小的代码：

from PyQt4 import QtGui
import sys
import ui_sof_test  #Gui File
from matplotlib.ticker import AutoMinorLocator

class Gui(QtGui.QMainWindow, ui_sof_test.Ui_MainWindow):

    def __init__(self):        
        super(self.__class__, self).__init__()        
        self.setupUi(self)
        self.call_test()
    def call_test(self):
        x = [1,2,3,4,5,6,7,8,9,10]
        y = [1000,2000,3000,4000,5000,6000,7000,8000,9000,10000]
        self.plot_test(x,y)
    def plot_test(self, x, y):        
        ax1 = self.mplwidget.axes
        fig = self.mplwidget.figure #Add a figure 
        ax1.plot(x, y, 'k', linestyle = "solid", linewidth = 1)
        ax1.plot(x, y, "ro")        
        #Log scale
        ax1.set_xscale('log')
        ax1.set_yscale('log')
        #format tick labels
        ax1.axis([1, 20, 100, 100000])
        #set Limits        

        #Gridlines
        #Plot y axis minor tick marks

        minorLocatory = AutoMinorLocator()
        ax1.yaxis.set_minor_locator(minorLocatory)
        ax1.tick_params(which='both', width= 0.5)
        ax1.tick_params(which='major', length=7)
        ax1.tick_params(which='minor', length=4, color='k')
        ax1.minorticks_on()
        #Make Border of Chart White
        fig.set_facecolor('white')
        #Plot Grid        
        ax1.grid(b=True, which='both', color='k', linestyle='-')    

        #Draw Chart
        fig.canvas.update()
        fig.canvas.draw()    

def main():
    app = QtGui.QApplication(sys.argv)  # A new instance of QApplication
    form = Gui()  # We set the form to be our ExampleApp (design)
    form.show()  # Show the form
    app.exec_()  # and execute the. app

if __name__ == '__main__':  # if we're running file directly and not importing it
    main()  # run the main function
 `

这是从PYQT4 UI文件创建的python代码。只需将其保存为ui_sof_test.py：

from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(1441, 705)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.tabWidget = QtGui.QTabWidget(self.centralwidget)
        self.tabWidget.setGeometry(QtCore.QRect(0, 0, 1111, 671))
        self.tabWidget.setObjectName(_fromUtf8("tabWidget"))
        self.tab = QtGui.QWidget()
        self.tab.setObjectName(_fromUtf8("tab"))
        self.mplwidget = MatplotlibWidget(self.tab)
        self.mplwidget.setGeometry(QtCore.QRect(10, 20, 761, 461))
        self.mplwidget.setObjectName(_fromUtf8("mplwidget"))
        self.tabWidget.addTab(self.tab, _fromUtf8(""))
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 1441, 21))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

        self.retranslateUi(MainWindow)
        self.tabWidget.setCurrentIndex(0)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "Motor Tester", None))
        self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Test", None))

from matplotlibwidget import MatplotlibWidget

Answer 1

出于某种原因，在绘制第二个图时，第一个图从轴上移除解决方法是在绘制第二个绘图后手动添加第一个绘图。

line, = ax1.plot(x, y, 'k', linestyle = "solid", linewidth = 1)
line2, = ax1.plot(x, y, marker="o", color="red", ls="")  
ax1.add_artist(line)

因为原则上绘图程序工作正常（如下所示），原因需要是MatplotlibWidget的使用，我不确定它实际上做了什么。

但如果我们用

替换它

fig = Figure()
ax = fig.add_subplot(111)
self.mplwidget = FigureCanvas(fig)
self.tabWidget.addTab(self.mplwidget, _fromUtf8(""))

我们已导入

from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure

以后再使用

ax1 = self.mplwidget.figure.axes[0]

情节按预期显示。所以你可能会停止使用MatplotlibWidget，如果它引起了这样的奇怪问题。

<小时/> 显示原理绘图按预期工作的最小示例：

import matplotlib.pyplot as plt
from  matplotlib.ticker import AutoMinorLocator
import numpy as np

class C():
    def __init__(self):
        self.mplwidget = self
        self.figure = plt.figure()
        self.axes = self.figure.add_subplot(111)

    def plot_test(self, x, y):
        ax1 = self.mplwidget.axes
        fig = self.mplwidget.figure #Add a figure 
        ax1.plot(x, y, 'k', linestyle = "solid", linewidth = 1)
        ax1.plot(x, y, "ro")        
        #Log scale
        ax1.set_xscale('log')
        ax1.set_yscale('log')
        #format tick labels
        ax1.axis([1, 20, 100, 100000])
        #set Limits        

        #Gridlines
        #Plot y axis minor tick marks
        minorLocatory = AutoMinorLocator()
        ax1.yaxis.set_minor_locator(minorLocatory)
        ax1.tick_params(which='both', width= 0.5)
        ax1.tick_params(which='major', length=7)
        ax1.tick_params(which='minor', length=4, color='k')
        ax1.minorticks_on()
        #Make Border of Chart White
        fig.set_facecolor('white')
        #Plot Grid        
        ax1.grid(b=True, which='both', color='k', linestyle='-')         
        #Draw Chart
        fig.canvas.update()
        fig.canvas.draw()

x, y = np.linspace(1,20), np.logspace(2, 5)

c = C()
c.plot_test(x,y)
plt.show()

使用Matplotlib Widget同时绘制数据点和线

1 个答案: