By drivas - 8/12/2014
Hi!
I am looking for a way to make a picture element select from a different list depending on a trial name. For example I have two lists:
<list A> /items= (2, 5, 8, 1) </list>
<list B> / items = (3, 6, 4, 10) </list>
And my picture element looks like this:
<picture stim> /items = mypictures /select = <% list.listA.nextvalue %> </picture>
Would there be a way to dynamically change the "select" mode to <%list.listB.nextvalue%> with an /ontrialbegin clause? Is there another way? I could always hard code them but since my pictures can be either on the left or on the right, from category X or Y, and finally from pool A or B of a category, this would yield 2^3 picture elements with basically the same code which just seems like very bad programming to me.
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By Dave - 8/12/2014
Sure. You simply do<picture stim>/items = mypictures /select = values.myvalue </picture>
<trial Atrial> / ontrialbegin = [values.myvalue=list.A.nextvalue] ... </trial>
<trial Btrial> / ontrialbegin = [values.myvalue=list.B.nextvalue] ... </trial> |
By drivas - 8/12/2014
Wow. Thanks again for the fast reply!
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By drivas - 8/12/2014
I just realized something with my script. In fact, during the trial (which is actually a surveypage), I display two stimuli simultaneously and ask the subject to rate the similarity using a slider. This means that during a trial, I must fetch two picture elements, and thus using a value would make my script simply select the same image again.
<surveypage page> /stimulustimes= [0=pictureLeft, pictureRight] ... </surveypage>
<picture pictureLeft> /items= mypictures /select = values.myvalue ... </picture>
<picture pictureRight> /items= mypictures /select = values.myvalue ... </picture>
I would like my script to select the next value in the list after list.listA(or B).nextvalue. |
By Dave - 8/12/2014
You need to set the <list>s' /selectionrate appropriately, i.e. to 'always'. See the documentation for said attribute for details. In addition, you need two <values> entries. One for the left pic, another for the right. Populate them from the <list> /ontrialbegin as needed.
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