King regards.

I have dataset in which every observations is a vector, but some of them have partially missing values, example:

Y_1 =\begin{bmatrix} 1 & 2 & \text{NA} & 4 \end{bmatrix}^{\top}

How i can model it with stan?.

Right now my model looks like this:

```
data {
int N; // number of observations.
vector[K] y[N];
}
model {
for (t in 1:N) {
// mu and sigma are the regression mean and variance respectively, they were defined before.
y_vector[t] ~ multi_normal(mu[t], sigma)
}
```

Thanks.