Pyqt connecting to a button a function in another file which plots a graph

Question

I have a the following code which creates a plot using matplotlib:

plot.py

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure


class Canvas(FigureCanvas):

    def __init__(self, parent = None, width=5, height=10, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        FigureCanvas.__init__(self, fig)

    def plot(self):
        print("im plotting")
        current_data = [46.67, 50.0, 47.06, 50.0]
        ax = self.figure.add_subplot(111)
        ax.scatter(current_data, current_data)
        print(current_data)

This Canvas class is used here in another file:

guiwrapper.py

from PyQt5 import QtCore, QtGui, QtWidgets, uic
import driver
from plot import Canvas


baseUIClass, baseUIWidget = uic.loadUiType("mygui.ui")


class Logic(baseUIWidget, baseUIClass):
    def __init__(self, parent=None):
        super(Logic, self).__init__(parent)
        self.setupUi(self)

        canvas = Canvas(self, width=8, height=4)
        self.plot_location.addWidget(canvas)
        canvas.plot()
        #self.run_simulation.clicked.connect(canvas.plot)
        #self.run_simulation.clicked.connect(lambda: canvas.plot())

if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    ui = Logic(None)
    ui.show()
    sys.exit(app.exec_())

I simply cannot figure out why I am not able to plot the graph when clicking the run_simulation button. If I simply write canvas.plot(), the GUI opens fine with the graph in there, but connecting buttons to call that function doesn't work, the graph doesn't get plotted and never shows up.

Does anyone known what's going on here?

Answer 1

Try it:

from PyQt5 import QtCore, QtGui, QtWidgets  #, uic
#import driver
#from plot import Canvas

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure
import random


class Canvas(FigureCanvas):
    def __init__(self, parent = None, width=5, height=10, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        FigureCanvas.__init__(self, fig)

    def plot(self):
        print("im plotting")
        current_data = random.sample(range(100), 4) #[46.67, 50.0, 47.06, 50.0]  # +
        ax = self.figure.add_subplot(111)
        ax.scatter(current_data, current_data)
        ax.set_title('Graphique')
        print(current_data)

#baseUIClass, baseUIWidget = uic.loadUiType("mygui.ui")


class Logic(QtWidgets.QWidget):         #(baseUIWidget, baseUIClass):
    def __init__(self, parent=None):
        super(Logic, self).__init__(parent)
#        self.setupUi(self)

        self.canvas = Canvas(self, width=8, height=4)
        self.plot_location = QtWidgets.QGridLayout(self)
        self.plot_location.addWidget(self.canvas)
        self.canvas.plot()

        self.run_simulation = QtWidgets.QPushButton("Update Graphique")       
        self.run_simulation.clicked.connect(self.canvasPlot)

        self.plot_location.addWidget(self.run_simulation)

    def canvasPlot(self):                                        # +++
        self.canvas.figure.clf()
        self.canvas.plot()
        # Draw Graph
        self.canvas.draw()


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    ui = Logic() #(None)
    ui.show()
    sys.exit(app.exec_())