Millisecond Forums

## Redefine value in each trial

https://forums.millisecond.com/Topic13447.aspx

 By skotturi - 6/2/2014 Dear Community, I am trying to use the Prospective Time Estimation task provided by Inquisit. Instead of just doing one trial at a fixed time interval of 53 seconds, I am trying to do multiple trials of random length. Instead of using:.../timeinterval = 5300I'm using:.../timeinterval = ceil(rand(45,75))*1000To achieve a random time interval in between 45 & 75 seconds. I'm currently just running two experiment blocks:/blocks = [1 = timeestimationstart, 2=timeestimationstart]This works except that the time interval variable isn't reassigned the second time, so my interval is the same for both trials. I have tried to force the reevaluation of the timeinterval variable:/stimulustimes = [0=start, circle]/timeout = [values.timeinterval = ceil(rand(45, 75))*1000]/branch = [trial.end]/recorddata = falseBut this fails with "Expression '[values.timeinterval' is invalid. Expression contains an unknown element or property name."I could just hardcode a second timeinterval, a second trial and second variable to be exported but I'd prefer a more elegant solution. It's been a while since I've coded much in Inquisit, been spending most of my time in python, js & R. Thus I'm undoubtedly over thinking this, I think...The code I'm working with can be found here (the prospective task): http://www.millisecond.com/download/library/TimeEstimation/Cheers, Sante By Dave - 6/2/2014 #1:Values are -- by design -- static. I.e. the expression in .../timeinterval = ceil(rand(45,75))*1000will get evaluated once and then values.timeinterval will remain unchanged. It is supposed to.#2:This.../timeout = [values.timeinterval = ceil(rand(45, 75))*1000]...is simply invalid syntax. The correct way to express it would be simply.../timeout = ceil(rand(45, 75))*1000...#3:The proper way to do this is.../timeinterval = 5300.../ontrialbegin = [values.timeinterval = ceil(rand(45, 75))*1000]/timeout = values.timeinterval... By skotturi - 6/3/2014 Great, that works and makes a lot more sense. The /ontrialbegin method was just what I was looking for!Cheers, Sante