Trying to replicate the Gabor patch from the book "Python for experimental psychologist"

JR088

Hi !

I bought the book "Python for experimental psychologists" and I am at the Gabor patch section. I am using the package WinPyhton-PyGaze-0.6.0

My "constants.py" code has the following parameters :

DISPSIZE = (1920, 1080)

DISPTYPE = 'psychopy'

My "experiment.py" code for the gabor patch replicates the book code with the Pygaze version

import pygaze

from psychopy.visual import GratingStim

from pygaze.display import Display

from pygaze.screen import Screen

import pygaze.libtime as timer

disp = Display()

gabor = GratingStim(pygaze.expdisplay, tex='sin', mask='gauss', sf=0.05, size=200)

gaborscreen = Screen()

gaborscreen.screen.append(gabor)

disp.fill(gaborscreen)

disp.show()

timer.pause(1000)

disp.close()

But I got the following error message and I don't get it, so if you help me, it would be great, thanks a lot !

FreeType import Failed: expected string or Unicode object, NoneType found

Traceback (most recent call last):

 File "experiment.py", line 21, in <module>

  disp = Display()

 File "C:\Users\JEANR\Documents\WinPython-PyGaze-0.6.0\WinPython-PyGaze-0.6.0\python-2.7.3\lib\site-packages\pygaze\display.py", line 45, in __init__

  self.__class__.__init__(self, **args)

 File "C:\Users\JEANR\Documents\WinPython-PyGaze-0.6.0\WinPython-PyGaze-0.6.0\python-2.7.3\lib\site-packages\pygaze\_display\psychopydisplay.py", line 70, in __init__

  screen=self.screennr, units='pix')

 File "C:\Users\JEANR\Documents\WinPython-PyGaze-0.6.0\WinPython-PyGaze-0.6.0\python-2.7.3\lib\site-packages\psychopy\visual\window.py", line 237, in __init__

  self.scrWidthCM = self.monitor.getWidth()

AttributeError: 'NoneType' object has no attribute 'getWidth'

0.8789 ERROR  avbin.dll failed to load.

           Try importing psychopy.visual as the first library

           (before anything that uses scipy)

           and make sure that avbin is installed.

0.8931 ERROR  avbin.dll failed to load.

           Try importing psychopy.visual as the first library

           (before anything that uses scipy)

           and make sure that avbin is installed.

0.9754 WARNING     Creating new monitor...

Edwin

Looks like PsychoPy didn't set up a default monitor. You could pass your own one to the Display when creating it, e.g. by doing the following:

from psychopy.monitors import Monitor

# Create a new monitor. Set the width and height to values that
# match your own setup. They are the screen's width and height
# as measured in centimetres.
my_monitor = Monitor("Freddy", width=32.0, height=18.0)

# Now pass the monitor to the Display.
disp = Display(monitor=my_monitor)

P.S. We're working on an update of this book; should be out later this year. Given the changes to Python, PyGaze, and PsychoPy, it's quite necessary!

JR088

Thank you for the reply ! I am looking forward reading the new version of the book .

I did the following :

# "JR" is the name of my laptop

# 39 and 21 are the actual size of the screen in cm

my "constants.py" file has the following parameter :

DISPSIZE = (1920, 1080)

DISPTYPE = 'psychopy'

And I got the following error message, but, again, I can't resolve it

Edwin

Oh, sorry, looks like it assumes height! You can just drop that parameter.

my_monitor = Monitor("Freddy", width=32.0)

While we're on the topic, you could opt to set the distance between you and the screen (also in cm):

my_monitor = Monitor("Freddy", width=32.0, distance=67.0)

BTW, this is PsychoPy's API documentation on the Monitor class: https://psychopy.org/api/monitors.html

JR088

I wrote the line as such : my_monitor = Monitor("JR", width=39.0, distance = 67.0). I got the following. I won't bother you too much with this, I can try the "Psychopy" version of the code that is also in the book

JR088

Just for information, with the pure Psychopy version of the code, the stim is displayed but still got message error