Creating list or vector with numerical values & getting n-th element out of this list


Creating list or vector with numerical values & getting n-th...

Author
Message
Olga Kunina
Olga Kunina
Partner Member
Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)

Group: Forum Members
Posts: 4, Visits: 1

Hi everyone,


I am trying
to expand the source code for the IOWA-Gambling task available at the Inquisit
website. In this version the loss-values are selected randomly as follows:


 <expressions>


/ getlossdeck1
= noreplace(0, 0, 0, 0, 0, 150, 200, 250, 300, 350) 


</expressions>


By contrast,
I want to define a fixed sequence of loss values for loss values for each trail.
I want to choose the current value depending on how many cards were already
taken from the deck. Speaking more technically - I want to get the nth element
out of an array, vector or list with numerical values.


Therefore I
am trying to define something like a list or a vector with loss values (integer
values) for each trail.


 / loss_deck1
= (0, 0, 0, 0, 0, 150, 200, 250, 300, 350) 


 Since that
did not work I have defined a counter


 <counter
deck1_loss>


/ items = (0,
0, 0, 0, 0, 150, 200, 250, 300, 350)


/ select = sequence(1-10)


</counter>


 Additionally,
I have introduced a variable "values.cards_deck1" that counts how
often deck1 was chosen. This counter is updated in each trial.


In the last
step I try to define the loss value for the current trial as:


/ getlossdeck1
= getitem(counter.deck1_loss.items, values.cards_deck1)


But each
time I get the error message "Expression is not valid. Item not found".


Does
someone have an idea whether it is possible to create a list or vector with
numerical values & get back a specific element out of this list?


Thanks a
lot for your help in advance.


Best regards, 


Olga Kunina


Dave
Dave
Supreme Being
Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)

Group: Administrators
Posts: 9.8K, Visits: 46K

Hmm, glancing over the code you posted, I think


/ getlossdeck1
= getitem(counter.deck1_loss.items, values.cards_deck1)


should be changed to a /ontrialend or /ontrialbegin expression:


<values>
/ getlossdeck1 = 0
[...]
</values>


and then


<trial sometrial>
/ ontrialbegin = [values.getlossdeck1=getitem(counter.deck1_loss, values.cards_deck1]
[...]
</trial>


If that doesn't do the trick, you might want to attach your script to this thread (-> see 'Options' tab when posting a reply).


~Dave


Olga Kunina
Olga Kunina
Partner Member
Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)

Group: Forum Members
Posts: 4, Visits: 1

Hi Dave,


 thank you
very much for your quick answer.  I have
followed your suggestions and changed my code as follows:


 <trial
igtfeedback>


   / ontrialbegin
= [ if (trial.igt.response == "deck1") { [..]


    values.loss
= getitem(counter.deck1_loss, values.cards_deck1); [..] }]


 </trial>


 Unfortunately
it does not work. It seems to be a problem with the expression "getitem(counter.deck1_loss,
values.cards_deck1)".


 I have
uploaded the script. Thanks a lot for taking time to answer the questions,


Best regards,


Olga


Attachments
IowaGamblingTask_final.exp (575 views, 8.00 KB)
Dave
Dave
Supreme Being
Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)

Group: Administrators
Posts: 9.8K, Visits: 46K

 Unfortunately
it does not work. It seems to be a problem with the expression "getitem(counter.deck1_loss,
values.cards_deck1)".


What exactly isn't working?


Dave
Dave
Supreme Being
Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)

Group: Administrators
Posts: 9.8K, Visits: 46K

Okay, I had a quick look at your script and compared it to the original IGT script available from millisecond.com. Well, if all you want is a fixed sequence of losses for each deck, there's a much easier way to pull this off. In the original script, losses are randomly determined by the following expressions:


<expressions>
/ getlossdeck1 = noreplace(0, 0, 0, 0, 0, 0, 0, 0, 0, 1250)
/ getlossdeck2 = noreplace(0, 0, 0, 0, 0, 150, 200, 250, 300, 350)
/ getlossdeck3 = noreplace(0, 0, 0, 0, 0, 0, 50, 50, 50, 50)
/ getlossdeck4 = noreplace(0, 0, 0, 0, 0, 0, 0, 0, 0, 250)
</expressions>


Each time the subject selects e.g. deck1, a random value is returned from expressions.getlossdeck1 (without replacement). Now, if you want to switch that behavior to a predictable, fixed sequence in which certain amounts of losses should occur, you may simply define:


<expressions>
/ getlossdeck1 = sequence(0, 0, 0, 0, 0, 0, 0, 0, 0, 1250)
/ getlossdeck2 = sequence(0, 0, 0, 0, 0, 150, 200, 250, 300, 350)
/ getlossdeck3 = sequence(0, 0, 0, 0, 0, 0, 50, 50, 50, 50)
/ getlossdeck4 = sequence(0, 0, 0, 0, 0, 0, 0, 0, 0, 250)
</expressions>


I.e.only when the subject selects deck1 for the tenth time, a loss of 1250 will occur. No further changes are necessary as you can see from the attached script.


Let me know if that helps,


~Dave


Attachments
igt_sequential.exp (581 views, 7.00 KB)
Olga Kunina
Olga Kunina
Partner Member
Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)

Group: Forum Members
Posts: 4, Visits: 1

Dear Dave,


thank you so much for your help. That is indeed a very simple soultion for this probelm. [BigGrin]


However, we are developing a new card risking task and there it would be helpful to be able to get the n-th element of a counter. Unfortunatelly there are not many examples for the usage of the function getitem in the documentation .




getitem(counter.deck, 1)

getitem(text.presenteditems, text.presenteditems.itemcount)

getitem(item.useritems, item.useritems.itemcount - 1)


Can you tell me how one would have to define "counter.deck", "text.presenteditems", or "item.useritems" so that this function is executed regularely?


Kind regards,


Olga




Dave
Dave
Supreme Being
Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)

Group: Administrators
Posts: 9.8K, Visits: 46K

Can you tell me how one would have to define "counter.deck", "text.presenteditems", or "item.useritems" so that this function is executed regularely?


Hmm, I don't think there's much more too it. Let's do this by way of an example. Suppose you have defined a counter element:


<counter fruit>
/ items = ("apple", "banana", "cherry", "damson", "elderberry")
[...]
</counter>


Now, suppose you want to retrieve the third item from the counter, i.e. "cherry", with the getitem function. You can use that function either by way of the <expressions> element


<expressions>
/ getcherry = getitem(counter.fruit, 3)
[...]
</expressions>


or by way of Inquisit's event attributes ('/ onexptbegin', '/ onexptend', '/ onblockbegin', '/ onblockend', '/ ontrialbegin', '/ ontrialend') available at the <expt>, <block> and <trial> level


<trial getcherry>
/ ontrialbegin = [text.favoritefruit.item.1 = getitem(counter.fruit, 3)]
/ stimulusframes = [favoritefruit]
[...]
</trial>

<text favoritefruit>
[...]
</text>


and do all sorts of things with it, e.g. write it to a <text> element or to a <values> entry. Note that the item index number, i.e. the second argument of the getitem function  ( 3 for "cherry") may also be a variable. So you might as well define another <values> entry (or use anything that returns a valid numerical value) and use it as the functions argument:


<values>
/ cherryindex = 3
[...]
</values>


<expressions>

/ getcherry = getitem(counter.fruit, values.cherryindex)

[...]

</expressions>


Best wishes from a fellow Inquisit user,


~Dave


Olga Kunina
Olga Kunina
Partner Member
Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)Partner Member (875 reputation)

Group: Forum Members
Posts: 4, Visits: 1

Dear Dave,


thanks for these examples and your answers. They were very helpfull. [Smile]


Have a good weekend. With best wishes,


Olga


Dave
Dave
Supreme Being
Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)Supreme Being (678K reputation)

Group: Administrators
Posts: 9.8K, Visits: 46K

You're welcome. BTW, if you're into risk-taking card tasks, definitely check out the Columbia Card Task script available from the Inquisit Task Library.


Cheers,


~Dave


fasteddie9141
fasteddie9141
Respected Member
Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)Respected Member (350 reputation)

Group: Forum Members
Posts: 2, Visits: 32
Dave

I know I'm dredging this from the mists of time but I am also trying to do a linear sequence with the iowa gambling task from the web scripts.

I have used the sequence command to select a fixed loss value and modified other elements of the script so that it only shows one value for loss gain over the card

Its 90% there but I cannot get the getlossdeck sequence to step together so that it doesn't step back when users select a different response.

i.e if they keep hitting deck A the cards are in correct sequence but if they change from deck to deck it does the decks in order but not so the sixth card in A leads to the 7th in B etc

Is there a simple way of explaining your example of counters so that I can get the existing code to step in time so to speak 

I have some code you can look at to see the modifications I've made if it would help

J
Tags
GO


Reading This Topic


Login
Existing Account
Email Address:


Password:


Social Logins

Select a Forum....






Millisecond Forums


Search