ar1_to_gm.RdTakes AR1 values and transforms them to GM
ar1_to_gm(theta, freq)A vec that contains AR1 values.
A double indicating the frequency of the data.
A vec containing GM values.
The function takes a vector of AR1 values \(\phi\) and \(\sigma ^2\) and transforms them to GM values \(\beta\) and \(\sigma ^2_{gm}\) using the formulas: \(\beta = - \frac{{\ln \left( \phi \right)}}{{\Delta t}}\) \(\sigma _{gm}^2 = \frac{{{\sigma ^2}}}{{1 - {\phi ^2}}} \)