Using matplotlib checkbuttons in PyQT5

Question

Is it possible to use matplotlib checkbuttons in a plot embedded in PyQT5? The code is below, the plot works and it is embedded in a PyQT window but the checkbuttons do not add or remove the series as they should. Code works fine when taken out of PyQT.

import numpy as np
import sys
from matplotlib.widgets import CheckButtons
from PyQt5.QtWidgets import QDialog, QApplication, QPushButton, QVBoxLayout
from PyQt5 import QtCore
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar
import matplotlib.pyplot as plt


class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        self.figure = plt.figure()
        t = np.arange(0.0, 2.0, 0.01)
        s0 = np.sin(2*np.pi*t)
        s1 = np.sin(4*np.pi*t)
        s2 = np.sin(6*np.pi*t)

        self.figure, ax = plt.subplots()
        l0, = ax.plot(t, s0, visible=False, lw=2, color='k', label='2 Hz')
        l1, = ax.plot(t, s1, lw=2, color='r', label='4 Hz')
        l2, = ax.plot(t, s2, lw=2, color='g', label='6 Hz')
        plt.subplots_adjust(left=0.2)

        self.lines = [l0, l1, l2]

        # Make checkbuttons with all plotted lines with correct visibility
        rax = plt.axes([0.05, 0.4, 0.1, 0.15])
        self.labels = [str(line.get_label()) for line in self.lines]
        visibility = [line.get_visible() for line in self.lines]
        check = CheckButtons(rax, self.labels, visibility)
        check.on_clicked(self.b)
##        print('showing')
##        plt.show()


        self.canvas = FigureCanvas(self.figure)
        layout = QVBoxLayout()
##        layout.addWidget(self.toolbar)
        layout.addWidget(self.canvas)
        # layout.addWidget(self.button)
        self.setLayout(layout)

        self.canvas.draw()
##        print('done')
##        plt.show()

    def b(self,label):
        index = self.labels.index(label)
        self.lines[index].set_visible(not self.lines[index].get_visible())
        plt.draw()

if __name__ == '__main__':
    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())

Answer 1

If you are going to use matplotlib with Qt then you should not use pyplot but the Figure that is set on the canvas. Also "check" must be a member of the class.

Considering the above, the solution is:

from PyQt5.QtWidgets import QApplication, QDialog, QVBoxLayout

import numpy as np
from matplotlib.backends.backend_qt5agg import FigureCanvas
from matplotlib.figure import Figure
from matplotlib.widgets import CheckButtons


class Window(QDialog):
    def __init__(self, parent=None):
        super(Window, self).__init__(parent)

        self.canvas = FigureCanvas(Figure(figsize=(5, 3)))

        t = np.arange(0.0, 2.0, 0.01)
        s0 = np.sin(2 * np.pi * t)
        s1 = np.sin(4 * np.pi * t)
        s2 = np.sin(6 * np.pi * t)

        ax = self.canvas.figure.subplots()
        (l0,) = ax.plot(t, s0, visible=False, lw=2, color="k", label="2 Hz")
        (l1,) = ax.plot(t, s1, lw=2, color="r", label="4 Hz")
        (l2,) = ax.plot(t, s2, lw=2, color="g", label="6 Hz")

        self.canvas.figure.subplots_adjust(left=0.2)

        self.lines = [l0, l1, l2]

        rax = self.canvas.figure.add_axes([0.05, 0.4, 0.1, 0.15])

        self.labels = [str(line.get_label()) for line in self.lines]
        visibility = [line.get_visible() for line in self.lines]

        self.check = CheckButtons(rax, self.labels, visibility)
        self.check.on_clicked(self.on_clicked)

        lay = QVBoxLayout(self)
        lay.addWidget(self.canvas)

        self.resize(640, 480)

    def on_clicked(self, label):
        index = self.labels.index(label)
        self.lines[index].set_visible(not self.lines[index].get_visible())
        self.canvas.draw()


def main():
    import sys

    app = QApplication(sys.argv)

    main = Window()
    main.show()

    sys.exit(app.exec_())


if __name__ == "__main__":
    main()