}
public static void main(String[] args) throws FileNotFoundException
{
// Using the function: 1/4 x^4 - 1/2 x^2 + 1/2 y^2
IEnergyModel pot = potNew.multivariateFromExpression(new String[]{"x","y"},
"1/4 x^4 - 1/2 x^2 + 1/2 y^2", // function expression
"x^3-x", "y"); // derivatives
// integrator
IDoubleArray masses = doublesNew.arrayFrom(1.0, 1.0);
double dt = 0.1, gamma = 1, kT = 0.2;