Const correctness

include/system.hpp

@@ -6,13 +6,15 @@
 template<typename value_t, typename drum_t, typename grabber_t, typename sysparams_t, typename force_t, typename coupler_t, typename driver_t, typename stepper_t>
 class System{
         public:
-                System(value_t t_end, value_t dt, std::vector<drum_t> drums, stepper_t stepper, force_t force, sysparams_t sysparams, grabber_t grabber)
+                System(const value_t t_end, const value_t dt, const std::vector<drum_t>& drums, const stepper_t stepper, const force_t force, const sysparams_t sysparams, const grabber_t grabber)
                         : drums_(drums), stepper_(stepper), force_(force), sysparams_(sysparams), grabber_(grabber), t_end_(t_end), dt_(dt), time_(0.)
                 {
                         sysparams_.coupler.precompute(t_end, dt, drums);
                         sysparams_.driver.precompute(t_end, dt, drums);
                         grabber_.init(t_end, dt, drums, sysparams.adjacency_vector);
 
+                        push_dc(); //push the initial values
+
                 }
                 ~System() = default;
 
@@ -49,7 +51,7 @@ class System{
                 }
 
         private:
-                void step_dc(value_t dt){
+                void step_dc(const value_t dt){
                         sysparams_.coupler.step(dt);
                         sysparams_.driver.step(dt);
                 }