Investment adjustment cost equation codes in Dynare

General DSGE Modeling
1

Hi.
I want to enter the codes of investmen Adjustment cost equation in Dynare.
Model is not in log-linear form.
I do not know how
to enter S(It/It-1) and S’(It/It-1) and S"(It/It-1) in Dynare.

It is investment in time t.
It-1 is investment in time t-1.
S’ is the first derivative and S" is the second derivate.

2

Use
S(\frac{I_t}{I_{t-1}})=\frac{\kappa}{2}\left(\frac{I_t}{I_{t-1}}-1\right)^2
with
S'(\frac{I_t}{I_{t-1}})=\kappa\left(\frac{I_t}{I_{t-1}}-1\right)
and
S''(\frac{I_t}{I_{t-1}})=\kappa

3

Thank you so much professor.