text: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  """
  Demo: Using an arbitrary numpy array as a visual stimulus.
  
  Also illustrates logging DEBUG level details to the console.
  """
  
  from __future__ import division
  
  from psychopy import visual, event, core, logging
  import numpy
  
  logging.console.setLevel(logging.DEBUG)
  
  win = visual.Window([600, 600], allowGUI=False)
  
  noiseTexture = numpy.random.rand(128, 128) * 2.0 - 1
  patch = visual.GratingStim(win, tex=noiseTexture,
      size=(128, 128), units='pix',
      interpolate=False, autoLog=False)
  
  while not event.getKeys():
      # increment by (1, 0.5) pixels per frame:
      patch.phase += (1 / 128.0, 0.5 / 128.0)
      patch.draw()
      win.flip()
  
  win.close()
  core.quit()
  
  # The contents of this file are in the public domain.
  