Millisecond Forums

Thank you Dave, yes simple lists like that work fine! Starting from a simple list helped me identify the issue actually. The problem occurs when the list elements have a /select attribute. I don't know why that is. I managed to achieve the final result by having multiple image elements and calling a list of those images in my surveypage (i.e., /questions = [1=list.images; 2=...]. This is very handy!

picture.name.item(index): "index" here merely means that the function expects a numerical value that ultimately represents a valid item number for the given <picture> element. I.e. if the give <picture> element has 10 items, then any numerical value between 1 and 10 (inclusive) will work. How that value is provided, does not really matter:

It could be

picture.name.item(list.somelist.nextvalue)

with

<list somelist>
/ items = (2,4,6,8)
</list>

or

picture.name.item(values.somevalue)

where values.somevalue has been set to a valid index number between 1 and 10.

<values>
/ somevalue  = 5
</values>

(or at runtime via /ontrialbegin = [values.somevalue = list.somelist.nextvalue])

The error you mentioned -- "A parameter of result was out of range" -- would indicate that the number you supplied is not in the valid range, e.g. if the <picture> has 10 items and you supply a value of, say, 13 you should see this kind of error.

This will hopefully allow you to determine where the mistake is.

Sorry Dave I thought that the function works only for index--> picture.name.item(index) as per the manual. I will try that now. -- Just tried it now it doesn't work - error is "A parameter of result was out of range" which makes sense if only the index is supposed to go in that parenthesis. Anyway, thanks for the help, might need to live with the disappearing pictures in surveypages :) 

Sorry Dave I thought that the function works only for index--> picture.name.item(index) as per the manual. I will try that now.

If you want to retrieve a given value, you simply use the nextvalue property instead of the nextindex property.

Hi Dave, 
Apart from the item index is there any way we can have specific item values? I have nested lists unfortunately so that the index would call the index of a selected list and so on- see below (only one example).

<list food_ratings>
/ items = [list.go_savoury.nextvalue; list.go_sweet.nextvalue; list.nogo_savoury.nextvalue; list.nogo_sweet.nextvalue; list.filler_savoury.nextvalue; list.filler_sweet.nextvalue]
/ selectionrate = trial
/ select = values.ratings_set
</list>

<list go_savoury>
/ items = (list.foodA.nextvalue, list.foodB.nextvalue, list.foodC.nextvalue)
/ selectionrate = always
/ select = values.go_savoury
</list>

<list foodA>
/ items = (1,2,3)
/ selectionrate = always
/ resetinterval = 0
/ itemprobabilities = uniform
</list>

Thanks, 
Loukia

You should be able to do something like this:
<surveypage mypage>
/ questions = [1=img_a; 2=img_b; 3=img_c]
</surveypage>

<image img_a>
/ items = ("<%picture.mypicture.item(list.mylist.nextindex)%>")
</image>

<image img_b>
/ items = ("<%picture.mypicture.item(list.mylist.nextindex)%>")
</image>

<image img_c>
/ items = ("<%picture.mypicture.item(list.mylist.nextindex)%>")
</image>

<picture mypicture>
/ items = myitems
</picture>

<item myitems>
/ 1 = "01.jpg"
/ 2 = "02.jpg"
/ 3 = "03.jpg"
/ 4 = "04.jpg"
/ 5 = "05.jpg"
/ 6 = "06.jpg"
</item>

<list mylist>
/ poolsize = 6
/ selectionrate = always
</list>