title: Live plotting of many subplots using pyqtgraph
body: <p>I used <a href="https://stackoverflow.com/questions/40126176/fast-live-plotting-in-matplotlib-pyplot">this</a> question and tried to use it to do fast live plotting of many subplots.</p>
  
  <p>Unfortunately it is very difficult for me to understand the code and thus I have problems changing it for my needs.</p>
  
  <p>I wanted to create a subplot of 2x2 matrices with 10x10 pixels. Right now I am getting the following:</p>
  
  <p><a href="https://i.stack.imgur.com/6wwYa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6wwYa.png" alt="enter image description here"></a></p>
  
  <p>The code looks like that:</p>
  
  <pre><code>from pyqtgraph.Qt import QtCore, QtGui
  import pyqtgraph as pg
  import numpy as np
  import time
  import sys
  
  class App(QtGui.QMainWindow):
      def __init__(self, parent=None):
          super(App, self).__init__(parent)
  
          #### Create Gui Elements ###########
          self.mainbox = QtGui.QWidget()
          self.setCentralWidget(self.mainbox)
          self.mainbox.setLayout(QtGui.QVBoxLayout())
  
          self.canvas = pg.GraphicsLayoutWidget()
          self.mainbox.layout().addWidget(self.canvas)
  
          self.label = QtGui.QLabel()
          self.mainbox.layout().addWidget(self.label)
  
          self.view = self.canvas.addViewBox()
          self.view.setAspectLocked(True)
          self.view.setRange(QtCore.QRectF(0, 0, 50, 50))
  
          self.img = []
          for i in range(4): 
              self.img.append(pg.ImageItem(None, border="w"))
              self.canvas.nextRow()
              self.view.addItem(self.img[i])
  
          self._update()
  
      def _update(self):
          for i in range(4):
              self.data = np.random.rand(10,10)
              self.img[i].setImage(self.data)
  
          QtCore.QTimer.singleShot(1, self._update)
  
  def sensor_data(n_sensors, x_res, y_res):
      return np.random.rand(n_sensors, x_res, y_res)
  
  if __name__ == '__main__':
      while True:
          # Get sensor data
          data = sensor_data(4, 10, 10)
          # Pass data to live plot function?
  
      app = QtGui.QApplication(sys.argv)
      thisapp = App()
      thisapp.show()
      sys.exit(app.exec_())
  </code></pre>
  
  <p>Can someone please show me what I'm doing wrong?</p>