Stimuli size in excel file not exactly the same when run in PsychoPy

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OS Mac Ventura 13.0
PsychoPy version 2022.2.4

I need to have a particular size of stimulus, however, when I input my excel file with the sizes I want, they are never displayed at the correct size when the experiment runs.

I have tried changing the screen units in the experimental settings to ‘cm’ as that is the units my stimuli are in & this stops the experiment running when it reaches the first stimulus.

Any suggestions on how to make this work?

Hello lpymg5

do you mind showing us the relevant screenshot of your Excel-file and the component in which you try to set the stimulus size?

Best wishes Jens

Thank you for your reply!

Screenshot 2022-12-16 at 14.41.21
My excel-file is simply just the stimulus size

This is the polygon component in which I have set the stimulus size

My screen settings when set to any other unit than “cm”, the experiment runs fine - although the polygons are not presented at the same size stated in the excel-file. As soon as I change that unit setting to “cm” the experiment will not progress past the first stimulus.

Thank you!


the parameter Size requires two arguments, width and height. You provide only one. I suggest using one column in your Excel-file for width and one for height.

Best wishes Jens