Stimuli Presentation Coordinates.

booradley

Hi Folks,

I'm presenting varying lengths of strings/text via a list in a SketchPad in OpenSesame.

I was wondering: is there anyway to record the x-y coordinates in the output file?

When using unique SketchPads for text typed into them I can hover the mouse over each letter/area and see the x-y coordinates but obviously I can't do this when using a list to pull the stimuli from.

This will be especially important when considering 'areas of interest' when I eventually set up an eye-tracking experiment in a few weeks.

Any insight would be appreciated.

Thanks,

Boo.

sebastiaan

Hi Boo,

You can. As of OpenSesame 3.2, each Canvas element has a rect property that will give you the bounding box around the element. Like so:

c = Canvas()
c['my_text'] = Text('Hi!')
x, y, w, h = c['my_text'].rect
print(x, y, w, h)

If you want to get the coordinates of an element on a sketchpad, you can do this in a similar way, provided that you have given the element a name. So say that there's an element called my_text on a sketchpad called welcome, then you could get the bounding box like so:

x, y, w, h = items['welcome'].canvas['my_text'].rect
print(x, y, w, h)

Then if you want to log this information, you simply have to assign the coordinates to an experimental variable, i.e. a property of the var object:

var.my_text_rect = 'x:{}, y:{}, w:{}, h:{}'.format(x, y, w, h)

Cheers!
Sebastiaan

booradley

Hi Sebastiaan,

That's awesome. Thanks!

Boo.