Embed Matplotlib into PyQt as a custom widget - qt

Question

I was trying embed matplotlib in python into Qt Designer as a custom widget, i followed one of those instruction online, i promote the widget to mplwidget.py and i coded file as code following
from PyQt4 import QtGui
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
class MplCanvas(FigureCanvas):
def __init__(self):
self.fig = Figure()
self.ax = self.fig.add_subplot(111)
FigureCanvas.__init__(self, self.fig)
FigureCanvas.setSizePolicy(self,
QtGui.QSizePolicy.Expanding,
QtGui.QSizePolicy.Expanding)
FigureCanvas.updateGeometry(self)
class MplWidget(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.canvas = MplCanvas()
self.vbl = QtGui.QVBoxLayout()
self.vbl.addWidget(self.canvas)
self.setLayout(self.vbl)
I gives me the error
Traceback (most recent call last):
File "C:\Users\l.cen\Documents\Guiexmaple\main.py", line 8, in <module>
from window import Ui_MainWindow
File "C:\Users\l.cen\Documents\Guiexmaple\window.py", line 106, in <module>
from mplwidget import MplWidget
File "C:\Users\l.cen\Documents\Guiexmaple\mplwidget.py", line 9, in <module>
class MplCanvas(FigureCanvas):
File "C:\Users\l.cen\Documents\Guiexmaple\mplwidget.py", line 22, in MplCanvas
FigureCanvas.updateGeometry(self)
NameError: name 'self' is not defined
so i delete the setSizePolicy and updateGeometry part
then it will give
Traceback (most recent call last):
File "C:\Users\l.cen\Documents\Guiexmaple\main.py", line 83, in <module>
window= Main()
File "C:\Users\l.cen\Documents\Guiexmaple\main.py", line 74, in __init__
self.ui.setupUi(self)
File "C:\Users\l.cen\Documents\Guiexmaple\window.py", line 34, in setupUi
self.widget = MplWidget(self.centralwidget)
TypeError: __init__() takes exactly 1 argument (2 given)
I'm not sure what happened exactly since i followed all the steps in the instruction, anything suggestions that could relate to this would be great.
if it helps, this is code for my main body:
import sys
from PyQt4 import QtGui, QtCore
from window import Ui_MainWindow
import sqlite3
import os
import matplotlib.pyplot as plt
from datetime import datetime
import calendar
import numpy
os.chdir("C:\Data")
conn = sqlite3.connect('FBG.db')
c=conn.cursor()
class Main(QtGui.QMainWindow):
def searching_database(self):
self.ui.listWidget.clear()
data = self.ui.Inputname.text()
for df in c.execute("select name from sqlite_master where type='table'; "):
strdf=str(df)
if len(data)==0:
break
if strdf[3:(len(data)+3)] == data: # the name for df start from position 3 due to "[u "
self.ui.listWidget.addItem(strdf[3:-3])
else:
pass
def delete_selection(self):
self.ui.listWidget_3.takeItem(self.ui.listWidget_3.currentRow())
def clear_graph(self):
self.ui.listWidget_3.clear()
def adding_items(self):
global b
b=self.ui.listWidget.currentItem().text()
b=str(b)
def plot_graph(self):
self.ui.listWidget_3.addItem(b)
time1= QtCore.QDateTime(self.ui.dateTimeEdit.dateTime())
date1 = time1.toPyDateTime()
timestamp1 = calendar.timegm(date1.utctimetuple()) #return a integer value
time2= QtCore.QDateTime(self.ui.dateTimeEdit_2.dateTime())
date2 = time2.toPyDateTime()
timestamp2 = calendar.timegm(date2.utctimetuple())
time=[]
data=[]
for df in c.execute('''select * from '''+ b ):
time= numpy.append(time, df[0])
data= numpy.append(data, df[1])
plt.scatter(time,data,label= b)
plt.title("Time versus strain or temperture")
plt.xlabel("Time")
plt.ylabel("Strain or temperature")
plt.legend()
plt.show()
def __init__(self):
QtGui.QMainWindow.__init__(self)
self.ui = Ui_MainWindow()
self.ui.setupUi(self)
self.ui.Inputname.textChanged.connect(self.searching_database)
self.ui.listWidget.itemClicked.connect(self.adding_items)
self.ui.pushButton.clicked.connect(self.plot_graph)
self.ui.Delete.clicked.connect(self.delete_selection)
self.ui.Clear.clicked.connect(self.clear_graph)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
window= Main()
window.show()
app.exec_()

Answer 1

Here is a piece of code that might help you
#!/usr/bin/python
import sys
from PyQt4.QtGui import QWidget, QPushButton, QMainWindow, QMdiArea, QVBoxLayout, QApplication
from PyQt4.QtCore import Qt
from pylab import *
from matplotlib.backends.backend_qt4agg import (
FigureCanvasQTAgg as FigureCanvas,
NavigationToolbar2QTAgg as NavigationToolbar)
class MyMainWindow(QMainWindow):
def __init__(self, parent=None):
"""
"""
super(MyMainWindow,self).__init__(parent)
self.setWidgets()
def setWidgets(self, ):
vBox = QVBoxLayout()
mainFrame = QWidget()
self._plotGraphButton = QPushButton("Plot Random Graph")
self._plotGraphButton.clicked.connect(self.plotRandom)
self._fig = figure(facecolor="white")
self._ax = self._fig.add_subplot(111)
self._canvas = FigureCanvas(self._fig)
self._canvas.setParent(mainFrame)
self._canvas.setFocusPolicy(Qt.StrongFocus)
vBox.addWidget(self._plotGraphButton)
vBox.addWidget(self._canvas)
vBox.addWidget(NavigationToolbar(self._canvas,mainFrame))
mainFrame.setLayout(vBox)
self.setCentralWidget(mainFrame)
def plotRandom(self, ):
"""
"""
x = linspace(0,4*pi,1000)
self._ax.plot(x,sin(2*pi*rand()*2*x),lw=2)
self._canvas.draw()
if __name__ == '__main__':
qApp = QApplication(sys.argv)
MainWindow = MyMainWindow()
MainWindow.show()
sys.exit(qApp.exec_())
Cheers