Randomization of sketchpad duration

rlaycock

Hi, I'm new to OpenSesame and python.

I want a sketchpad to have a randomized duration (eg between 400 and 1000 ms).

I found this discussion which seems to be exactly what I want: https://forum.cogsci.nl/discussion/1975/solved-randomized-duration-of-sketchpad-presentation

So, I have added an inline script with:

import random
var.stim_duration = random.randint(400,1000)

Then I have my sketchpad with duration listed as [stim_duration], including the square brackets.

When I run the task, it terminates, and indicates that "The variable 'stim_duration' does not exist"

When I look at my variable inspector, stim_duration is listed (though it is not bolded).

What am I doing wrong?

Robin

lvanderlinden

Hi @rlaycock ,

Welcome to the forum and good to hear that you got so far in finding the solution! :)

It sounds like you are trying to use the variable "stim_duration" before it defined in the inline_script item. Did you make sure that:

• You placed the inline_script item before the sketchpad that uses [stim_duration]?
• You placed the Python script in the Prepare tab (and not in the Run tab) of the inline_script item?

For more information about OpenSesame's prepare-run strategy, see here:

• https://osdoc.cogsci.nl/3.3/manual/prepare-run/

If this doesn't solve the issue, feel free to upload your experiment here so that we can have a closer look.

Cheers,

Lotje

rlaycock

@lvanderlinden

Hi Lotje,

many thanks for your reply. And thanks also for fixing this issue!

I did have the inline script before my sketchpad, but I was not aware of the difference between Prepare and Run. Once I put in in Prepare that fixed it.

Thanks again.

Robin

lvanderlinden

Great Robin, thanks for getting back to us with the solution! :)