serial animation in pyqt4

Question

This is what I have adapted my code to with the init functions: I think I'm confused at how inheritance works with graphing applications. I have added my constants to the init function of the figure canvas, but they do not come down to the subclasses. I thought that is how the inheritance works.

import sys
import os
from PyQt4 import QtGui
from PyQt4 import QtCore
import functools
import numpy as np
import random as rd
matplotlib.use("Qt4Agg")
from matplotlib.animation import TimedAnimation
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
import matplotlib.pyplot as plt
import matplotlib.animation as animation
import serial


class CustomMainWindow(QtGui.QMainWindow):
    def __init__(self):
        super(CustomMainWindow, self).__init__()

        # Define the geometry of the main window
        self.setGeometry(300, 300, 800, 400)
        self.setWindowTitle("my first window")

        # Create FRAME_A
        self.FRAME_A = QtGui.QFrame(self)
        self.FRAME_A.setStyleSheet("QWidget { background-color: %s }" % QtGui.QColor(210,210,235,255).name())
        self.LAYOUT_A = QtGui.QGridLayout()
        self.FRAME_A.setLayout(self.LAYOUT_A)
        self.setCentralWidget(self.FRAME_A)

        # Place the matplotlib figure
        self.myFig = CustomFigCanvas()
        self.LAYOUT_A.addWidget(self.myFig, *(0,1))
        self.show()  

class CustomFigCanvas():
    def __init__(self):
        fig, ax = plt.subplots()
        line, = ax.plot([], [], lw=2)
        ax.grid()
        xdata, ydata = [], []
        plt.suptitle('TEST DATA', fontsize=20)
        plt.xlabel('TIME in seconds')
        plt.ylabel('FORCE in pounds')
        plt.show()

    def data_gen(t=0):
        cnt = 0
        while cnt < 2000:
            cnt += 1
            t += .2
            with serial.Serial('COM3', baudrate = 115200, timeout=1) as port:
                x = port.readline().replace(' lbf','')
            yield t, x
            print t, x

    def graph():

        ax.set_ylim(-20, 55000)
        ax.set_xlim(0, 10)
        del xdata[:]
        del ydata[:]
        line.set_data(xdata, ydata)
        return line,

    def run(data):
        # update the data
        t, y = data
        xdata.append(t)
        ydata.append(y)
        xmin, xmax = ax.get_xlim()

        if t >= xmax:
            ax.set_xlim(xmin, 2*xmax)
            ax.figure.canvas.draw()
        line.set_data(xdata, ydata)

        return line,


if __name__== '__main__':
    app = QtGui.QApplication(sys.argv)
    QtGui.QApplication.setStyle(QtGui.QStyleFactory.create('Plastique'))
    myGUI = CustomMainWindow()


    sys.exit(app.exec_())