PsychoPy Frequently Asked Questions

Troubleshooting

Features

PsychoPy is slow to start on Mac OS X (PPC chips).

This seems to be a problem with Python on the Mac. Basically it takes a long while to import python libraries. If you're a competent programmer and Mac user then maybe you could help find a workaround. Update: Actually python on the new Intel macs is not slow at all

PsychoPy IDE is sluggish, especially with big scripts.

PsychoPyIDE does a fair bit of analysis on the code that you write in order to be able to provide help in the source assistant panel and in the form of autocompletion. If you load up a large script (>500 lines) or a large number of them, the analysis will take time, especially when you first start the IDE. In this case you may want to sacrifice autocompletion and help functions by turning off "Analyse on file save/open" (Tools menu) and turn off the Source Assistant (View menu).

When I run a demo or program nothing happens or only a window comes up and then disappears. What's wrong?

It's essentially impossible to tell what's wrong with this information, but probably python is giving a more useful error message just before it crashes. What you need to do is run the demo in such a way that when it does crash you get to see the text output (e.g. run the demo from PsychoPyIDE).

Why do I get an error that python couldn't import the xxxxx module?

Often this is just that you haven't installed that module and PsychoPy or some other library needs it.

Why doesn't PsychoPy manage to import OpenGL or GLUT even though I have PyOpenGL installed?

This could be due to a few different problems:

  1. your graphics card driver might not support OpenGL (only for very old systems)
  2. your graphics card might need a new driver. The drivers that ship natively within WindowsXP don't generally support OpenGL. Download and install the drivers from manufacturer's website (e.g. nvidia, ATI)
  3. the glut32.dll library might not be on the path. This file is included with the PsychoPy kitchen sink package and installed by default to c:\python24 but that path needs to be added to your environment variables (see Installation).

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Why doesn't my window appear in the correct position?

For some reason pygame hasn't always used the latest version of the SDL library on which it was built. You can fetch the latest version from this page. Download the latest 'Runtime Library' for your platform, unzip it and replace the appropriate file (e.g. SDL.dll) in site-packages/pygame with the one you just downloaded.

How do I upgrade to a new version of PsychoPy?

Just install the new version over the top of the old one.

What graphics card should I get?

See System Requirements Goto Top

I want to run experiments with sub-millisecond accuracy. Can PsychoPy do that?

Actually this on e is popular enough to have it's own FAQ. See Timing Issues Goto Top

Can I communicate with a parallel port?

Yes, but using a couple of other packages, rather than PsychoPy itself. See details here

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