# Oo_.mean from 3rd-order approximation?

The 1st and 2nd order approximation give

but 3rd order approximation doesn’t. How to get the theoretical mean when I use 3rd order?

Most probably because you are requesting theoretical moments, which are not yet implemented at

If you use the

option, the field will be there.

Dear Prof. Pfeifer,

```stoch_simul(order = 3, periods=0, nograph, irf=0); ```
However, I still couldn’t find `oo_.mean`Did I make a mistake using the “periods” option?