drift diffusion model error

[Carina Forster]

Hello Bayesians,

I would like to see if my data fits a drift diffusion model. Attached you will find my data (I have 33 subjects in total, its only an example).

If I run a choiceRT_ddm model using that data, I get the following error:

Stan model 'choiceRT_ddm' does not contain samples.

as well as this error for the initial value in chain 1:

Rejecting initial value:

Chain 1:   Error evaluating the log probability at the initial value.

Chain 1: Exception: validate transformed params: tau[1] is 0.0338836, but must be greater than or equal to 0.1  (in 'model384c763e527d_choiceRT_ddm' at line 44)

I am assuming it might be the Reaction time, but I don't see why? 

Further: subjects have two choices in each trial (right vs. left key), their decision is based on a random dot task but additionally we have a feature that predicts the correct choice in each trial perfectly (from a later block on).

Anyone an idea what model I could use or might try? 

Thank you so much for your help. 

Carina

[Woo-Young Ahn]

Hi Carina, 

I'm sorry for the delayed reply. Could you also include your R or Python code so that we can replicate the error? Also, please keep that in mind that data file should be a *.txt file. 

Best,

Young