These routines compute the initial conditions for a periodic orbit of a non-autonomous with periodic dependence on time:
That is, the goal is to compute a point
![$ x^*$](/a-granados/PO_periodic_systems/raw/master/img2.png)
![$ t_0$](/a-granados/PO_periodic_systems/raw/master/img3.png)
The method used consists on performing a Newton method to solve the equation
where
![$ S_{t_0}$](/a-granados/PO_periodic_systems/raw/master/img6.png)
![$ qT$](/a-granados/PO_periodic_systems/raw/master/img7.png)
The program needs the gsl libraries, and can be compiled using
g++ -o main main.c rk78.c lu.c memory.c -lgsl -lgslcblas