Different round() behaviour online and desktop

Builder
1

OS Win10
PsychoPy version v2022.1.2
Standard Standalone? yes

I have built an experiment in which participants are asked to adjust a slider. The value of the slider is displayed above it. To achieve this I have used a code component to define “thisPos”

thisPos = slider.getMarkerPos()

And then a text component to display the number:

$'Current rating: ’ + str(round(thisPos, 2))

This is done so that the number displayed is rounded to 2dp, instead of being a very long string. Weirdly this works completely fine online, but when trying to run it in the builder on my desktop, I get this error:

ratingText.setText('Current rating: ’ + str(round(thisPos, 2)), log=False)
TypeError: type NoneType doesn’t define round method

I would much rather be able to test the experiment on the desktop, so any help in understanding why the behaviours differ would be much appreciated.

2

Hi, this is happening because the slider doesn’t have a start value so if you set a start value, it should fix the error. Although, if you do not want a start value, you can set the text component start time to condition and in the field, use slider.rating. This means that this component only starts when there is a rating.

3

So in my code component I have thisPos = 0 in the Begin Routine tab. Is this what you mean?

4

Hi, not really. I made a minimal demo to demonstrate what I was referring to in my previous comment.

show_slider_rating.psyexp (12.3 KB)

1 Like
5

Thanks! This makes sense now