Dear all.

I’m trying to fit a 2-component Gaussian mixture model using brms. Let’s say I have two covariates, x and z, that I want to use to model the two means, mu1 and mu2. In addition I would like to add the constraint that the effect of x is the same on both mu1 and mu2 while the effect of z is component specific.

I’m using splines so my first approach looks something like this:

```
m <- brm(bf(y ~ 1,
mu1 ~ s(x) + s(z),
mu2 ~ s(x) + s(z)),
dTotal,
family = mixture(gaussian, gaussian),
iter = 10^4,
chains = 4,
cores = 4)
```

which works, but now I would like to add the restriction that the the `s(x)`

term is exactly the same for mu1 and mu2 while the two `s(z)`

terms are different. Is that possible?

Thanks in advance!