For bringing a vector into the `integrate_ode`

function, could I assign the vector as a single element in an array of reals `x_r`

? For example,

```
data {
vector[5] test_vector;
}
transformed data {
real x_r[10];
x_r[1] = test_vector;
}
```

Is that a possible operation? If not, the plan was to use the `to_array_1d`

function to convert the vector into an array of reals.