[solved] Using Parallel plug-in in OpenSesame

Comments

• Josh

  November 2015 edited 1:50AM

  Hi,

  I have no experience in using the parallel plug-in myself (and I've also heard that it is a bit unstable), but I do think this is achievable without the parallel plug-in in the first place. How well it works depends on the desired frequencies though; very high frequencies may not be displayed properly.
  The idea would be to create 4 canvases in an inlinescript, one for each 'state', i.e., a canvas with two squares on, a canvas with one square on and one square off, etc. In the run phase, you start a timer by means of start_time = self.time(). Next, you keep track of time in a while-loop, and present the canvases accordingly. Say these are the frequencies and states (1 for on, -1 for off):

    square1_freq = 12
    square2_freq = 8
    square1_state = 1
    square2_state = 1 
  

  As an example, you want the second square to go on/off at 1/8*1000 milliseconds and all multiplications of this value. Hence, you get something like this:

    end_reached = False
    stimuli_presentation_duration = 2000
  
    current_multiplication_sq1 = 1
    current_multiplication_sq2 = 1      
    while end_reached == False:
           canvas_change = False
           current_time = self.time() - start_time
           if current_time >= float(1)/square1_freq*1000*current_multiplication_sq1:
                 square1_state = square1_state * -1
                 current_multiplication_sq1 += 1
                 canvas_change = True
           if current_time >= float(1)/square2_freq*1000*current_multiplication_sq2:
                 square2_state = square2_state * -1
                 current_multiplication_sq2 += 1
                 canvas_change = True
  
           if canvas_change == True:
                 if square1_state == 1 and square2_state == 1:
                        canvas1.show()
                 elif square1_state == -1 and square2_state == 1:
                        canvas2.show()
                 elif square1_state == 1 and square2_state == -1:
                        canvas3.show()
                 elif square1_state == -1 and square2_state == -1:
                        canvas4.show()
  
           if current_time >= stimuli_presentation_duration:
                 end_reached = True      
  

  Let me know if this works.

  Cheers,

  Josh
• Sachinthana

  November 2015 edited November 2015

  Hi Josh,

  Thanks for the tip.
  I'm a kinda new to OpenSesame and it took me a while to understand the use of inline code. I compiled the code and run it with 4 sketchpads c1, c2, c3, c4 in the experiment modifying your code as shown below.

  
  start_time = self.time()
  
  square1_freq = 12
  square2_freq = 8
  square1_state = 1
  square2_state = 1
  
  canvas1 = canvas()
  canvas2 = canvas()
  canvas3 = canvas()
  canvas4 = canvas()
  
  canvas1.c1()
  canvas2.c2()
  canvas3.c3()
  canvas4.c4()
  
  end_reached = False
  stimuli_presentation_duration = 2000
  
  current_multiplication_sq1 = 1
  current_multiplication_sq2 = 1      
  
  while end_reached == False:
  
      canvas_change = False
      current_time = self.time() - start_time
      if current_time >= float(1)/square1_freq*1000*current_multiplication_sq1:
          square1_state = square1_state * -1
          current_multiplication_sq1 += 1
          canvas_change = True
      if current_time >= float(1)/square2_freq*1000*current_multiplication_sq2:
          square2_state = square2_state * -1
          current_multiplication_sq2 += 1
          canvas_change = True
  
      if canvas_change == True:
          if square1_state == 1 and square2_state == 1:
              canvas1.show()
          elif square1_state == -1 and square2_state == 1:
              canvas2.show()
          elif square1_state == 1 and square2_state == -1:
              canvas3.show()
          elif square1_state == -1 and square2_state == -1:
              canvas4.show()
  
      if current_time >= stimuli_presentation_duration:
          end_reached = True
  
  

  But it reported me the following error.

  
    File "dist\libqtopensesame\misc\process.py", line 140, in run
    File "dist\libopensesame\experiment.py", line 390, in run
    File "dist\libopensesame\item_store.py", line 94, in execute
    File "dist\libopensesame\item_store.py", line 126, in prepare
    File "dist\libopensesame\sequence.py", line 106, in prepare
    File "dist\libopensesame\item_store.py", line 126, in prepare
    File "dist\libopensesame\sketchpad.py", line 103, in prepare
    File "dist\openexp\_canvas\xpyriment.py", line 98, in prepare
    File "dist\expyriment\stimuli\_visual.py", line 752, in plot
    File "dist\expyriment\stimuli\_visual.py", line 289, in surface_size
    File "dist\expyriment\stimuli\_visual.py", line 391, in _get_surface
    File "dist\expyriment\stimuli\_rectangle.py", line 112, in _create_surface
    error: Invalid resolution for Surface
  
  

  Can you please help me to get out of this?

  Cheers.

  Sachinthana
• Josh

  November 2015 edited 1:50AM

  Hi Sachinthana,

  How did you construct (i.e. place the squares on) your canvases? At first glance it seems to me that something went wrong there. You could try to present your canvases in a simplified manner, like this:

     canvas1.show()
     self.sleep(5000)
     canvas2.show()
     self.sleep(5000)   # et cetera.
  

  and see if that works normally.

  Cheers,

  Josh
• Sachinthana

  November 2015 edited 1:50AM

  Hey Josh,

  It worked. Thank you very much.