URL of experiment: https://run.pavlovia.org/Iida/muller-lyer-modified/html
Description of the problem: TypeError: undefined is not an object (evaluating ‘this._vertices_px.map’)
Hi all, I would like to conduct the online experiment about Muller-Lyer illusion in Japan.
In this experiment, participants will be required to adjust the length of the test line without arrows by dragging their mouse so that the adjusted length of the test line equals that of the other line with arrows. Clicking the OK button leads to the next trial.
I have the error described above (TypeError: undefined is not an object (evaluating ‘this._vertices_px.map’) in adjusting the length of the test line.
I suspect that there is something wrong with the codes in “each frame”.
Here is the codes,
xy = mouse.getRel();
probeLen = Math.min(0.7, Math.max(0.3, probeLen+xy));
Please let me know if you have any good idea.