title: Kivy graph doesn't appear in widget
body: <p>I'm trying to find a solution to embed a graph within a kivy widget. There seems to be only one example of using kivy garden graph (sin wave) and I'm having difficulty implementing this within my app. </p>
  
  <p>Here is the code that I'm working with </p>
  
  <pre><code>#!/usr/bin/kivy
  import kivy
  
  
  from random import random
  from kivy.app import App
  from kivy.lang import Builder
  from kivy.uix.screenmanager import ScreenManager, Screen
  from kivy.uix.gridlayout import GridLayout
  from kivy.uix.boxlayout import BoxLayout
  from kivy.uix.button import Button
  from kivy.uix.switch import Switch
  from kivy.uix.label import Label
  from kivy.garden.graph import Graph, MeshLinePlot
  from math import sin
  import matplotlib.pyplot as plt
  import matplotlib.animation as animation
  from kivy.graphics import *
  
  from kivy.config import Config
  Config.set('graphics', 'width', '800')
  Config.set('graphics', 'height', '480')
  
  Builder.load_string("""
  
  &lt;Menuscreen&gt;:
      #Handling the gesture event.
      ScreenManager:
          id: manager
          Screen:
              id: main_screen
              name:'main_screen'
              FloatLayout:
  
                  MyGraph:
                      size_hint: None, None
                      size: 800,600
                      pos: 25,25
  
  
  
  """)
  
  class MyGraph(Graph):
      def __init__(self, **kwargs):
          super(MyGraph, self).__init__(**kwargs)
          self.xlabel = 'This is the X axis'
          self.ylabel = 'This is the Y axis'
          self.x_ticks_minor = 5
          self.x_ticks_major = 25
          self.y_ticks_major = 1
          self.y_grid_label = True
          self.x_grid_label = True
          self.x_grid = True
          self.y_grid = True
          self.xmax = 100
          self.xmin = -0
          self.ymin = -1
          self.ymax = 1
          self.plot = MeshLinePlot(color=[1, 0, 0, 1])
          self.plot.points = [(x, sin(x / 10.)) for x in range(0, 100)]
          self.add_plot(self.plot)
  
  class MenuScreen(Screen):
      pass
  
  sm = ScreenManager()
  menu_screen = MenuScreen(name='menu')
  sm.add_widget(menu_screen)
  
  
  class TestApp(App):
  
      def build(self):
  
          return sm
  
  if __name__ == '__main__':
      TestApp().run()
  </code></pre>
  
  <p>All of the axis labels seem to appear but the points on the graph do not appear. Is there something that I am missing to get this to appear? Thanks in advance for your advice. </p>