I'm trying to use odeint
(i.e. library for solving differential equations) inside a class but I couldn't. I really need to put it inside a class so that I can have control over my project. This is the error I'm getting error C3867: 'robot::sys': function call missing argument list; use '&robot::sys' to create a pointer to member
and this is my code
#include <iostream>
#include <boost/numeric/odeint.hpp>
using namespace std;
using namespace boost::numeric::odeint;
/* The type of container used to hold the state vector */
typedef std::vector< double > state_type;
class robot
{
double g, dt, t;
runge_kutta_dopri5<state_type> stepper;
public:
state_type x;
robot() : x(2)
{
x[0] = 1.0;
x[1] = 0.0;
t = 0;
g = 0.15;
dt = 0.1;
}
void move();
void sys(const state_type &x, state_type &dx, double t);
};
void robot::move()
{
stepper.do_step(sys , x , t, dt );
t += dt;
}
void robot::sys( const state_type &x , state_type &dx , double t )
{
dx[0] = x[1];
dx[1] = -x[0] - g*x[1];
}
int main(int argc, char **argv)
{
robot Robo;
for ( size_t i(0); i < 100; ++i){
Robo.move();
}
return 0;
}
When I try the solution that is suggested in the error message, I'm getting another error which is
....\odeint\stepper\base\explicit_error_stepper_fsal_base.hpp(279): error C2064: term does not evaluate to a function taking 3 arguments
sys
is a non-static member function; they do not behave like normal functions because they have an implicitthis
parameter.Possible fixes are:
(1) Use a C++11 lambda in place of
sys
:(2) Keep
sys
and usestd::bind
orboost::bind
:(3) Use a custom-written functor instead of
sys
:Note that in this case you can have your class store a
System
object instead of storingg
and constructing it on each call tomove
.