Using an external measure as parameter value

[gabriel...@gmail.com]

Hello, 

I have a few neural measures as candidates for the main DDM parameters v, a and t0. My idea would be to use the values of all to predict behavior using just, e.g. the diffusion coefficient as a scaling parameter (thus the only estimated parameter).

I could code a relatively simple model to do specifically this but I would like to use the HDDM framework to make comparison with models where I relax the identity by estimating more parameters. Thus is there a way to use an identity link to estimate a parameter, e.g. `v = CPP` instead of a linear link `v ~ CPP`?

Best,

Gabriel