In a brms nonlinear formula, am I correct in thinking that `x * y`

means x \times y and not x + y + (x \times y) (as it does in a standard nonlinear formula).

That’s correct. Also, remember that you must specify both the parameters and the predictors in nonlinear formula, because the parameters are no longer implicit as per usual R formula. In addition, the parameters are actually place holders for linear predictors. See the vignette.

1 Like