Hi,

I have a model syntax that successfully compiles and fits simulated data with no issues. I am trying to add the generated quantities block to compute model fit indices with the loo package.

Does anyone have any suggestions? Thank you.

The model syntax is below. Please ignore any redundancy in the code pointed out by @Bob_Carpenter in another post. I will deal with it later.

```
data{
int I; // number of items
int P; // number of individuals
int n_obs; // number of observed responses
int item[n_obs]; // item id
int id[n_obs]; // person id
real Y[n_obs]; // vector outcome
}
parameters {
real beta[I]; // vector of beta parameters for
real ln_alpha[I]; // vector of alpha parameters for I items
real omega[I]; // vector of omega parameters for I items
real gamma0[I]; // vector of gamma0 parameters for I items
real gamma1[I]; // vector of gamma1 parameters for I items
real theta[P]; // vector of theta parameters for P individuals
}
transformed parameters{
real<lower=0> alpha[I];
for(i in 1:I){
alpha[i] = exp(ln_alpha[i]);
}
}
model{
beta ~ normal(0,10);
ln_alpha ~ normal(0,10);
omega ~ normal(0,10);
gamma0 ~ normal(0,10);
theta ~ normal(0,1);
for(i in 1:I){
gamma1[i] ~ normal(0,10)T[gamma0[i],];
}
for(i in 1:n_obs) {
real k0 = inv_logit(gamma0[item[i]] - alpha[item[i]]*theta[id[i]]);
real k1 = inv_logit(gamma1[item[i]] - alpha[item[i]]*theta[id[i]]);
if (Y[i] == 0) {
target += log(k0);
} else if (Y[i] == 1) {
target += log1m(k1);
} else {
real sh1 = exp((alpha[item[i]]*theta[id[i]] + beta[item[i]] + omega[item[i]])/2);
real sh2 = exp((-(alpha[item[i]]*theta[id[i]] + beta[item[i]]) + omega[item[i]])/2);
target += log(k1 - k0) + beta_lpdf(Y[i] | sh1,sh2);
}
}
}
```