Shuffle items in list to use same order of stimuli throughout experiment


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Jakob
Jakob
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After the fast reply to my last question I am trying it again. I am very suprised I couldn't find a previous post asking the same thing, because it appears to me to be a standard feature I am looking for:
I have four stimuli. I want the order of the stimuli randomized per subject at the beginning of the experiment (counterbalancing between subjects). Then I want to use the same order of stimuli at various points of the experiment. 
So lets say I have four stimuli:

<item Simuli_Portraits>
/1 = "flower1.jpg"
/2 = "flower2.jpg"
/3 = "flower3.jpg"
/4 = "flower4.jpg"
</item>

I could call a specific item in "picture" using select:
<picture Portrait1>
/ items = Simuli_Portraits
/ select = 1
</picture>

All I would need is a shuffeled array of numbers that I could call one by one via select, let's say
/select = order_stimuli(1), where order_stimuli is a random order of the numbers 1-4

I can also create a sequence of numbers via list:
<list order_stimuli>
/ items = (1,4)
/ selectionmode = random
/ selectionrate = experiment
</list>

Yet, what I don't understand is whether this really provides me a list of numbers or only one number. All I need is a function that shuffles an array of numbers, in which I can call the x-th element of the array.
I was also thinking about some workaround methods:
1. Manually creating all possible orders (a list of items with all combination "1234", "1243, "1324", ..., "4321") as randomly choosing one. Here again I have the problem that I don't know how to call the x-th element of the string/number/array for select in the picture function.
2. Using some complicated randomization with branches at the beginning of the experiment to create a randomized order in items, also not having a clue how that could work.

I am very much into the logic of (dynamical) indexing that I might miss the very obvious solution on how to keep randomization consistent throughout multiple blocks of the experiment. Thank you for your help!


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