Eye-tracking - Setting physical screen size and distance to participant

Comments

• brusil

  October 2017

  An inline script as follows seems to do the trick.

  from pygaze import settings
  
  settings.SCREENSIZE = (31.0, 17.4)  # physical display size (cm)
  settings.SCREENDIST = 60.0          # participant to display distance (cm)
  
  
• hanzh

  October 2017 edited October 2017

  Hi @brusil ,

  Did you find any consequences of leaving these parameters as default on your eye-tracking data? Do you have to set these parameters correctly to get the correct coordinates? Also calling @sebastiaan here!

  Thanks!
  Han
• brusil

  October 2017 edited October 2017

  Hi @hanzh,

  Since I'm new at this and I haven't yet been able to analyse my test data, I can't tell if these have consequences, but I don't think they do.
  Still, since they're printed to the eye-tracking data files, I prefer their value to be as close as possible to the reality.
  Probably @sebastiaan and @Edwin can tell for sure if this is of any relevance.

  Cheers,
  Bruno
• eduard

  October 2017

  The consequence of not changing them depends on how you analyze the data. For example, if you define regions of interest, based on degrees of visual angle, you will have incorrect regions when the screen parameters are off. Perhaps, it might also affect the parsing of saccades and fixations (particularly, for small saccades), but that depends on how these algorithms are implemented in Pygaze.

  Hope this helps.

  Eduard