[ACT-R-users] visual-location buffer query; tracking

[David.Kaethner at dlr.de]

Hello everyone,

I have two questions I could not answer by reading the manual.

1. I want to harvest the first chunk that is stuffed into the visual-location buffer after a scene change (SET-BUFFER-CHUNK VISUAL-LOCATION VISUAL-LOCATION0-0 REQUESTED NIL). To do that, I want to query the state of the buffer (if there are any chunks in it or not). Is there any way to do that? The visual-location buffer does not have a query like the visual buffer (state empty).

2. I'm trying to do some tests with the tracking feature. In order to do that, I obviously need a moving object first. I want to use the act-r-window with a simple loop that works like "add-text-to-exp-window -- clear-exp-window -- add-text-to-exp-window (at a new position)". The problem is that the model needs to run the entire time (instead of having it restarted like in Unit 3 of the tutorial).
- When do I call the model with the "run"-command? If I do it before the start of the loop, the model runs through and obviously can't detect anything since the window has not been executed yet. If I do it within the loop, the model is restarted.
- How often do I have to use the "install-device" command? Apparently everytime the model updates the scene (proc-display). But that feels odd, since I take it that install-device only tells the model which device it has to use. Why should I do that several times? If anyone has some example source-code for a tracking task that uses the act-r-window I'd be very interested.


Sincerely, David