Unable to convert object to a number

[wakecarter]

cm can’t work online, because the browser doesn’t know the size of the monitor.

Wakefield's Daily Tips

Use height units If you are using a head rest or controlled environment where you have set up the monitor details in the PsychoPy monitor centre then feel free to use cm or degrees. This is particularly recommended if you are presenting stimuli to two screens. On the other hand, if you aren’t controlling the distance between the participant and the computer or are running your study online, I would recommend using height units rather than pix or norm. In norm units the screen is 2 x 2 (bottom …

ScreenScale code | try it | discussion thread

Use to ask a participant to work out their screen scale relative to a credit card.
Morys-Carter, W. L. (2021, May 18). ScreenScale [Computer software]. Pavlovia. OSF | ScreenScale